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 (
    4817, 4674, 4693, 4816, 4695, 4675, 4688, 
    4656, 4820, 4830, 4663, 4834, 4694, 
    4690, 4664, 4453, 4655, 4510, 4671, 
    4815, 4075, 4455, 4452, 4689, 4687, 
    4437, 4826, 4657, 4662, 4242, 4829, 
    4469, 4691, 4692
  ) 
  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 0.00186

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "23.81"
    },
    "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": 34,
        "rows_produced_per_join": 6,
        "filtered": "19.99",
        "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`product_id` in (4817,4674,4693,4816,4695,4675,4688,4656,4820,4830,4663,4834,4694,4690,4664,4453,4655,4510,4671,4815,4075,4455,4452,4689,4687,4437,4826,4657,4662,4242,4829,4469,4691,4692))",
        "cost_info": {
          "read_cost": "23.13",
          "eval_cost": "0.68",
          "prefix_cost": "23.81",
          "data_read_per_join": "163"
        },
        "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)))"
      }
    }
  }
}