SELECT 
  cscart_product_prices.product_id, 
  MIN(
    IF(
      cscart_product_prices.percentage_discount = 0, 
      cscart_product_prices.price, 
      cscart_product_prices.price - (
        cscart_product_prices.price * cscart_product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  cscart_product_prices 
WHERE 
  cscart_product_prices.product_id IN (
    64444, 91021, 147592, 64844, 24954, 
    230551, 161304, 75723, 230548, 146346, 
    332753
  ) 
  AND cscart_product_prices.lower_limit = 1 
  AND cscart_product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  cscart_product_prices.product_id

Query time 0.00093

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "9.92"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "range",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "key": "usergroup",
        "used_key_parts": [
          "product_id",
          "usergroup_id",
          "lower_limit"
        ],
        "key_length": "9",
        "rows_examined_per_scan": 22,
        "rows_produced_per_join": 22,
        "filtered": "100.00",
        "cost_info": {
          "read_cost": "7.72",
          "eval_cost": "2.20",
          "prefix_cost": "9.92",
          "data_read_per_join": "704"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`unicomps`.`cscart_product_prices`.`lower_limit` = 1) and (`unicomps`.`cscart_product_prices`.`product_id` in (64444,91021,147592,64844,24954,230551,161304,75723,230548,146346,332753)) and (`unicomps`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}

Result

product_id price
24954 753.66000000
64444 306.09000000
64844 364.80000000
75723 227.87000000
91021 584.29000000
146346 917.40000000
147592 159.52000000
161304 323.77000000
230548 264.60000000
230551 289.76000000
332753 689.04000000