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 (
    10156, 10023, 10103, 10026, 10074, 10088, 
    10174, 10233, 10226, 10219, 10244, 
    10105, 10157, 10160, 10059, 9972, 10247, 
    10274, 10294, 10022, 10104, 10261, 
    9952, 10159, 10161, 10225, 10254, 10255, 
    10273, 9937, 9968, 10071, 10272, 9969, 
    10047, 10050, 10056, 10093, 10232, 
    10238
  ) 
  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 0.00236

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "46.01"
    },
    "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": 80,
        "rows_produced_per_join": 15,
        "filtered": "19.99",
        "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`product_id` in (10156,10023,10103,10026,10074,10088,10174,10233,10226,10219,10244,10105,10157,10160,10059,9972,10247,10274,10294,10022,10104,10261,9952,10159,10161,10225,10254,10255,10273,9937,9968,10071,10272,9969,10047,10050,10056,10093,10232,10238))",
        "cost_info": {
          "read_cost": "44.41",
          "eval_cost": "1.60",
          "prefix_cost": "46.01",
          "data_read_per_join": "383"
        },
        "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)))"
      }
    }
  }
}