SELECT 
  q_product_prices.product_id, 
  MIN(
    IF(
      q_product_prices.percentage_discount = 0, 
      q_product_prices.price, 
      q_product_prices.price - (
        q_product_prices.price * q_product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  q_product_prices 
WHERE 
  q_product_prices.product_id IN (
    10514, 10341, 10353, 10366, 10367, 10371, 
    10372, 10373, 10374, 10022, 10026, 
    10031, 10033, 10035, 10036, 10037, 
    10038, 10041, 10042, 10045, 10046, 
    10048, 10051, 8682, 8214, 4584
  ) 
  AND q_product_prices.lower_limit = 1 
  AND q_product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  q_product_prices.product_id

Query time 0.00096

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "62.41"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "q_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": 26,
        "rows_produced_per_join": 5,
        "filtered": "19.99",
        "index_condition": "(`portal`.`q_product_prices`.`product_id` in (10514,10341,10353,10366,10367,10371,10372,10373,10374,10022,10026,10031,10033,10035,10036,10037,10038,10041,10042,10045,10046,10048,10051,8682,8214,4584))",
        "cost_info": {
          "read_cost": "61.37",
          "eval_cost": "1.04",
          "prefix_cost": "62.41",
          "data_read_per_join": "124"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`portal`.`q_product_prices`.`lower_limit` = 1) and (`portal`.`q_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}