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 (
    10517, 10518, 10519, 10520, 10521, 10522, 
    10523, 10524, 10525, 10526, 10527, 
    10528, 10529, 10530, 10531, 10532, 
    10533, 10534, 10535, 10536, 10537, 
    10538, 10539, 10659
  ) 
  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 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "16.81"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "cscart_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": 4,
        "filtered": "20.00",
        "index_condition": "(`gaseus`.`cscart_product_prices`.`product_id` in (10517,10518,10519,10520,10521,10522,10523,10524,10525,10526,10527,10528,10529,10530,10531,10532,10533,10534,10535,10536,10537,10538,10539,10659))",
        "cost_info": {
          "read_cost": "16.33",
          "eval_cost": "0.48",
          "prefix_cost": "16.81",
          "data_read_per_join": "115"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`gaseus`.`cscart_product_prices`.`lower_limit` = 1) and (`gaseus`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}

Result

product_id price
10517 0.00000000
10518 0.00000000
10519 0.00000000
10520 0.00000000
10521 0.00000000
10522 0.00000000
10523 0.00000000
10524 0.00000000
10525 0.00000000
10526 0.00000000
10527 0.00000000
10528 0.00000000
10529 0.00000000
10530 0.00000000
10531 0.00000000
10532 0.00000000
10533 0.00000000
10534 0.00000000
10535 0.00000000
10536 0.00000000
10537 0.00000000
10538 0.00000000
10539 0.00000000
10659 0.00000000