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 (
    5725, 5726, 5727, 5728, 5729, 5730, 5731, 
    5732, 5733, 5734, 5735, 5736, 5737, 
    5738, 5739, 5740, 5741, 5742, 5743, 
    5744, 5745, 5746, 5747, 5748, 5749, 
    5750, 5751, 5752, 5753, 5754, 5755, 
    5756, 5757, 5758, 5759, 5760, 5761, 
    5762, 5763, 5764, 5765, 5766, 5767, 
    5768, 5769, 5770, 5771, 5772, 5773, 
    5774, 5775, 5776, 5777, 5778, 5779, 
    5780, 5781, 5782, 5783, 5784, 1986, 
    1987, 1988, 1989, 1990, 1991, 1992, 
    1993, 1994, 1995, 1996, 1997, 1998, 
    1999, 2000, 2001, 2002, 2003, 2004, 
    2005, 2006, 2007, 2008, 2009, 2010, 
    2011, 2012, 2013, 2014, 2015, 2016, 
    2017, 2018, 2019, 2020, 2021
  ) 
  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 0.00150

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "68.11"
    },
    "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": 98,
        "rows_produced_per_join": 19,
        "filtered": "20.00",
        "index_condition": "(`gaseus`.`cscart_product_prices`.`product_id` in (5725,5726,5727,5728,5729,5730,5731,5732,5733,5734,5735,5736,5737,5738,5739,5740,5741,5742,5743,5744,5745,5746,5747,5748,5749,5750,5751,5752,5753,5754,5755,5756,5757,5758,5759,5760,5761,5762,5763,5764,5765,5766,5767,5768,5769,5770,5771,5772,5773,5774,5775,5776,5777,5778,5779,5780,5781,5782,5783,5784,1986,1987,1988,1989,1990,1991,1992,1993,1994,1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020,2021))",
        "cost_info": {
          "read_cost": "66.15",
          "eval_cost": "1.96",
          "prefix_cost": "68.11",
          "data_read_per_join": "470"
        },
        "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
1986 0.00000000
1987 0.00000000
1988 0.00000000
1989 0.00000000
1990 0.00000000
1991 0.00000000
1992 0.00000000
1993 0.00000000
1994 0.00000000
1995 0.00000000
1996 0.00000000
1997 0.00000000
1998 0.00000000
1999 0.00000000
2000 0.00000000
2001 0.00000000
2002 0.00000000
2003 0.00000000
2004 0.00000000
2005 0.00000000
2006 0.00000000
2007 0.00000000
2008 0.00000000
2009 0.00000000
2010 0.00000000
2011 0.00000000
2012 0.00000000
2013 0.00000000
2014 0.00000000
2015 0.00000000
2016 0.00000000
2017 0.00000000
2018 0.00000000
2019 0.00000000
2020 0.00000000
2021 0.00000000
5725 0.00000000
5726 0.00000000
5727 0.00000000
5728 0.00000000
5729 0.00000000
5730 0.00000000
5731 0.00000000
5732 0.00000000
5733 0.00000000
5734 0.00000000
5735 0.00000000
5736 0.00000000
5737 0.00000000
5738 0.00000000
5739 0.00000000
5740 0.00000000
5741 0.00000000
5742 0.00000000
5743 0.00000000
5744 0.00000000
5745 0.00000000
5746 0.00000000
5747 0.00000000
5748 0.00000000
5749 0.00000000
5750 0.00000000
5751 0.00000000
5752 0.00000000
5753 0.00000000
5754 0.00000000
5755 0.00000000
5756 0.00000000
5757 0.00000000
5758 0.00000000
5759 0.00000000
5760 0.00000000
5761 0.00000000
5762 0.00000000
5763 0.00000000
5764 0.00000000
5765 0.00000000
5766 0.00000000
5767 0.00000000
5768 0.00000000
5769 0.00000000
5770 0.00000000
5771 0.00000000
5772 0.00000000
5773 0.00000000
5774 0.00000000
5775 0.00000000
5776 0.00000000
5777 0.00000000
5778 0.00000000
5779 0.00000000
5780 0.00000000
5781 0.00000000
5782 0.00000000
5783 0.00000000
5784 0.00000000