SELECT 
  product_prices.product_id, 
  MIN(
    IF(
      product_prices.percentage_discount = 0, 
      product_prices.price, 
      product_prices.price - (
        product_prices.price * product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  product_prices 
WHERE 
  product_prices.product_id IN (
    455184, 455717, 455720, 455721, 455722, 
    455746, 455747, 455756, 455757, 455758, 
    456518, 457021, 457033, 457034, 457042, 
    457045, 457052, 457065, 457078, 457783, 
    457789, 457790, 457795, 457805
  ) 
  AND product_prices.lower_limit = 1 
  AND product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  product_prices.product_id

Query time 0.00116

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "16.81"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "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": 24,
        "rows_produced_per_join": 2,
        "filtered": "10.00",
        "index_condition": "(`goimagine`.`product_prices`.`product_id` in (455184,455717,455720,455721,455722,455746,455747,455756,455757,455758,456518,457021,457033,457034,457042,457045,457052,457065,457078,457783,457789,457790,457795,457805))",
        "cost_info": {
          "read_cost": "16.57",
          "eval_cost": "0.24",
          "prefix_cost": "16.81",
          "data_read_per_join": "57"
        },
        "used_columns": [
          "id",
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`goimagine`.`product_prices`.`lower_limit` = 1) and (`goimagine`.`product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}

Result

product_id price
455184 2.45000000
455717 2.45000000
455720 18.00000000
455721 2.45000000
455722 2.45000000
455746 2.45000000
455747 2.45000000
455756 2.45000000
455757 18.00000000
455758 3.55000000
456518 3.55000000
457021 20.00000000
457033 2.45000000
457034 2.45000000
457042 2.45000000
457045 15.00000000
457052 2.45000000
457065 2.45000000
457078 3.55000000
457783 21.00000000
457789 18.00000000
457790 2.45000000
457795 2.45000000
457805 15.00000000