SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    258, 664, 663, 622, 627, 613, 619, 572, 
    363, 337, 298, 322, 505, 618, 562, 503, 
    486, 478, 291, 94, 323, 336, 371, 372, 
    405, 437, 632
  )

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "18.91"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": [
        "parent"
      ],
      "key": "parent",
      "used_key_parts": [
        "parent_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 27,
      "rows_produced_per_join": 27,
      "filtered": "100.00",
      "index_condition": "(`dbggbern`.`cscart_categories`.`parent_id` in (258,664,663,622,627,613,619,572,363,337,298,322,505,618,562,503,486,478,291,94,323,336,371,372,405,437,632))",
      "cost_info": {
        "read_cost": "16.21",
        "eval_cost": "2.70",
        "prefix_cost": "18.91",
        "data_read_per_join": "108K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ]
    }
  }
}