SELECT 
  cscart_product_prices.product_id, 
  MIN(
    IF(
      cscart_product_prices.percentage_discount = 0, 
      cscart_product_prices.price, 
      cscart_product_prices.price - (
        cscart_product_prices.price * cscart_product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  cscart_product_prices 
WHERE 
  cscart_product_prices.product_id IN (
    1477, 1177, 1178, 1179, 1184, 1180, 1181, 
    1164, 1165, 5316, 1186, 1187, 5855, 
    7353, 7413, 7414, 7415, 7416, 7417, 
    7418, 7421, 7861, 7862, 7863, 7864, 
    6273, 6274, 7570, 7571, 7572, 5706, 
    5130, 5129, 7077, 2471, 4801, 4802, 
    5467, 5469, 5472, 5468, 5466, 5470, 
    5465, 6934, 6935, 6933, 3190
  ) 
  AND cscart_product_prices.lower_limit = 1 
  AND cscart_product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  cscart_product_prices.product_id

Query time 0.00065

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "34.96"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "range",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "key": "product_id",
        "used_key_parts": [
          "product_id"
        ],
        "key_length": "3",
        "rows_examined_per_scan": 51,
        "rows_produced_per_join": 9,
        "filtered": "19.12",
        "index_condition": "(`dbggbern`.`cscart_product_prices`.`product_id` in (1477,1177,1178,1179,1184,1180,1181,1164,1165,5316,1186,1187,5855,7353,7413,7414,7415,7416,7417,7418,7421,7861,7862,7863,7864,6273,6274,7570,7571,7572,5706,5130,5129,7077,2471,4801,4802,5467,5469,5472,5468,5466,5470,5465,6934,6935,6933,3190))",
        "cost_info": {
          "read_cost": "33.98",
          "eval_cost": "0.98",
          "prefix_cost": "34.96",
          "data_read_per_join": "234"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`dbggbern`.`cscart_product_prices`.`lower_limit` = 1) and (`dbggbern`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}