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 (
    480228, 480236, 480263, 480271, 480272, 
    480276, 480788, 480798, 480815, 480816, 
    480824, 480829, 480835, 481553, 481594, 
    482105, 482110, 482114, 482116, 482138, 
    482876, 482886, 482893, 482897
  ) 
  AND product_prices.lower_limit = 1 
  AND product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  product_prices.product_id

Query time 0.00130

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "18.28"
    },
    "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 (480228,480236,480263,480271,480272,480276,480788,480798,480815,480816,480824,480829,480835,481553,481594,482105,482110,482114,482116,482138,482876,482886,482893,482897))",
        "cost_info": {
          "read_cost": "18.04",
          "eval_cost": "0.24",
          "prefix_cost": "18.28",
          "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
480228 18.00000000
480236 2.45000000
480263 6.35000000
480271 18.00000000
480272 20.00000000
480276 2.45000000
480788 18.00000000
480798 2.45000000
480815 2.45000000
480816 20.00000000
480824 2.45000000
480829 2.45000000
480835 2.45000000
481553 2.45000000
481594 18.00000000
482105 2.45000000
482110 2.45000000
482114 2.45000000
482116 2.45000000
482138 15.00000000
482876 2.45000000
482886 18.00000000
482893 2.45000000
482897 18.00000000