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 (
    32654, 32655, 32656, 32657, 32658, 32659, 
    32660, 32661, 32662, 32663, 32664, 
    32665, 32666, 32667, 32668, 32669, 
    32671, 32672, 32673, 32675, 32676, 
    32677, 32679, 32680, 32681, 32682, 
    32683, 32684, 32685, 32686, 32687, 
    32688
  ) 
  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 0.00162

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "76.81"
    },
    "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": 32,
        "rows_produced_per_join": 6,
        "filtered": "19.99",
        "index_condition": "(`portal`.`q_product_prices`.`product_id` in (32654,32655,32656,32657,32658,32659,32660,32661,32662,32663,32664,32665,32666,32667,32668,32669,32671,32672,32673,32675,32676,32677,32679,32680,32681,32682,32683,32684,32685,32686,32687,32688))",
        "cost_info": {
          "read_cost": "75.53",
          "eval_cost": "1.28",
          "prefix_cost": "76.81",
          "data_read_per_join": "153"
        },
        "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)))"
      }
    }
  }
}