SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 59 
WHERE 
  cscart_products_categories.product_id IN (
    4147, 2918, 4148, 2917, 2684, 7585, 3354, 
    2896, 3353, 2434, 2435, 2436, 3803, 
    1858, 1857, 1856, 1855, 5706, 5130, 
    5129, 7077, 6341, 5516, 5197, 7841, 
    3927, 3926, 3932, 1860, 2471, 5445, 
    5446, 3538, 3539, 1528, 1527, 4660, 
    4659, 4486, 4658, 6698, 2217, 2342, 
    2218, 3104, 3117, 7215, 6973
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00157

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "200.61"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 164,
            "rows_produced_per_join": 164,
            "filtered": "100.00",
            "index_condition": "(`dbggbern`.`cscart_products_categories`.`product_id` in (4147,2918,4148,2917,2684,7585,3354,2896,3353,2434,2435,2436,3803,1858,1857,1856,1855,5706,5130,5129,7077,6341,5516,5197,7841,3927,3926,3932,1860,2471,5445,5446,3538,3539,1528,1527,4660,4659,4486,4658,6698,2217,2342,2218,3104,3117,7215,6973))",
            "cost_info": {
              "read_cost": "69.41",
              "eval_cost": "16.40",
              "prefix_cost": "85.81",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "dbggbern.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 164,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "41.00",
              "eval_cost": "16.40",
              "prefix_cost": "143.21",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "dbggbern.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 8,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "41.00",
              "eval_cost": "0.82",
              "prefix_cost": "200.61",
              "data_read_per_join": "32K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status",
              "storefront_id"
            ],
            "attached_condition": "((`dbggbern`.`cscart_categories`.`storefront_id` in (0,1)) and ((`dbggbern`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`dbggbern`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`dbggbern`.`cscart_categories`.`usergroup_ids`))) and (`dbggbern`.`cscart_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}