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 (
    493, 409, 404, 456, 469, 431, 466, 402, 
    439, 484, 470, 490, 451, 491, 411, 486, 
    458, 459, 461, 462, 471, 425, 427, 416, 
    419, 464, 465, 432, 444, 445, 477, 478, 
    487, 488, 434, 435, 515, 481, 489, 415, 
    430, 414, 475, 452, 412, 417, 503, 514
  ) 
  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 0.00075

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "173.31"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "96.00"
      },
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "ALL",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "rows_examined_per_scan": 368,
        "rows_produced_per_join": 95,
        "filtered": "26.09",
        "cost_info": {
          "read_cost": "58.11",
          "eval_cost": "19.20",
          "prefix_cost": "77.31",
          "data_read_per_join": "2K"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`danishecarter_latest`.`cscart_product_prices`.`lower_limit` = 1) and (`danishecarter_latest`.`cscart_product_prices`.`product_id` in (493,409,404,456,469,431,466,402,439,484,470,490,451,491,411,486,458,459,461,462,471,425,427,416,419,464,465,432,444,445,477,478,487,488,434,435,515,481,489,415,430,414,475,452,412,417,503,514)) and (`danishecarter_latest`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}