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 (
    169, 42, 39, 40, 205, 37, 152, 160, 74, 
    73, 71, 75, 72, 108, 237, 191, 235, 70, 
    122, 115, 156, 90, 175, 196, 43, 104, 
    76, 129, 127, 121, 103, 95
  ) 
  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 0.00079

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "117.98"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "64.00"
      },
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "ALL",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "rows_examined_per_scan": 254,
        "rows_produced_per_join": 63,
        "filtered": "25.20",
        "cost_info": {
          "read_cost": "41.18",
          "eval_cost": "12.80",
          "prefix_cost": "53.98",
          "data_read_per_join": "1K"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`satishecarter_march_003`.`cscart_product_prices`.`lower_limit` = 1) and (`satishecarter_march_003`.`cscart_product_prices`.`product_id` in (169,42,39,40,205,37,152,160,74,73,71,75,72,108,237,191,235,70,122,115,156,90,175,196,43,104,76,129,127,121,103,95)) and (`satishecarter_march_003`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}