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 (
    4176, 4357, 4287, 4612, 4187, 4639, 4210, 
    4265, 4598, 4503, 4613, 4504, 4635, 
    4466, 4160, 4164, 4335, 4553, 4592, 
    4600, 4340, 4180, 4344, 4591, 4282, 
    4461, 4590, 4178, 4501, 4302, 4616, 
    4296, 4352, 4283, 4353
  ) 
  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 0.00150

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "24.51"
    },
    "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": 35,
        "rows_produced_per_join": 6,
        "filtered": "19.99",
        "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`product_id` in (4176,4357,4287,4612,4187,4639,4210,4265,4598,4503,4613,4504,4635,4466,4160,4164,4335,4553,4592,4600,4340,4180,4344,4591,4282,4461,4590,4178,4501,4302,4616,4296,4352,4283,4353))",
        "cost_info": {
          "read_cost": "23.81",
          "eval_cost": "0.70",
          "prefix_cost": "24.51",
          "data_read_per_join": "167"
        },
        "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)))"
      }
    }
  }
}