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 (
    33116, 33117, 33118, 33119, 33120, 33121, 
    33122, 33123, 33124, 33125, 33126, 
    33127, 33128, 33129, 33130, 33131, 
    33132, 33133, 33134, 33135, 33136, 
    33137, 33138, 33139, 33140, 33141, 
    33142, 33143, 33144, 33145, 33146, 
    33148
  ) 
  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 0.00097

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "79.61"
    },
    "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": 34,
        "rows_produced_per_join": 6,
        "filtered": "19.99",
        "index_condition": "(`portal`.`q_product_prices`.`product_id` in (33116,33117,33118,33119,33120,33121,33122,33123,33124,33125,33126,33127,33128,33129,33130,33131,33132,33133,33134,33135,33136,33137,33138,33139,33140,33141,33142,33143,33144,33145,33146,33148))",
        "cost_info": {
          "read_cost": "78.25",
          "eval_cost": "1.36",
          "prefix_cost": "79.61",
          "data_read_per_join": "163"
        },
        "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)))"
      }
    }
  }
}