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 (
    453, 454, 455, 450, 451, 452, 435, 439, 
    443, 430, 429, 428, 415, 416, 417, 418, 
    419, 420, 421, 422, 423, 424, 425, 426, 
    403, 404, 405, 406, 407, 408, 409, 410, 
    411, 412, 413, 414, 391, 392, 393, 394, 
    395, 396, 397, 398, 399, 400, 401, 402, 
    379, 380, 381, 382, 383, 384, 385, 386, 
    387, 388, 389, 390, 363, 364, 365, 366
  ) 
  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 0.00098

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "208.45"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "128.00"
      },
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "ALL",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "rows_examined_per_scan": 383,
        "rows_produced_per_join": 128,
        "filtered": "33.42",
        "cost_info": {
          "read_cost": "54.86",
          "eval_cost": "25.60",
          "prefix_cost": "80.46",
          "data_read_per_join": "3K"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`pankajecarter_systemfour`.`cscart_product_prices`.`lower_limit` = 1) and (`pankajecarter_systemfour`.`cscart_product_prices`.`product_id` in (453,454,455,450,451,452,435,439,443,430,429,428,415,416,417,418,419,420,421,422,423,424,425,426,403,404,405,406,407,408,409,410,411,412,413,414,391,392,393,394,395,396,397,398,399,400,401,402,379,380,381,382,383,384,385,386,387,388,389,390,363,364,365,366)) and (`pankajecarter_systemfour`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}