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 (
    10242, 8381, 10072, 10231, 10246, 10251, 
    10262, 10269, 10271, 10280, 10158, 
    10021, 10030, 10044, 10045, 10076, 
    10099, 10106, 10123, 10164, 10166, 
    10235, 10253, 10256, 10257, 10268, 
    10270, 10279, 10281, 10297, 9714, 10046, 
    10107, 10155, 10163, 10168, 10203, 
    10240, 10252, 10263, 10266, 10298, 
    10094, 10096, 10108, 10153, 10162, 
    10165, 10169, 10170, 10220, 10259, 
    10031, 10070, 10173, 10245, 10258, 
    10260, 10041, 10241, 10184, 10296, 
    10067, 10149, 10064
  ) 
  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 0.00117

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "81.06"
    },
    "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": 144,
        "rows_produced_per_join": 28,
        "filtered": "19.99",
        "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`product_id` in (10242,8381,10072,10231,10246,10251,10262,10269,10271,10280,10158,10021,10030,10044,10045,10076,10099,10106,10123,10164,10166,10235,10253,10256,10257,10268,10270,10279,10281,10297,9714,10046,10107,10155,10163,10168,10203,10240,10252,10263,10266,10298,10094,10096,10108,10153,10162,10165,10169,10170,10220,10259,10031,10070,10173,10245,10258,10260,10041,10241,10184,10296,10067,10149,10064))",
        "cost_info": {
          "read_cost": "78.18",
          "eval_cost": "2.88",
          "prefix_cost": "81.06",
          "data_read_per_join": "690"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`lower_limit` = 1) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}