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 (
    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, 
    2022, 2023, 2024, 2025, 2026, 2027, 
    2028, 2029, 2030, 2031, 2032, 2033, 
    2034, 2035, 2036, 2037, 2038, 5668, 
    5669, 5670, 5671, 5672, 5673, 5674, 
    5675, 5676, 5677, 5678, 5679
  ) 
  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 0.00133

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 (5754,5755,5756,5757,5758,5759,5760,5761,5762,5763,5764,5765,5766,5767,5768,5769,5770,5771,5772,5773,5774,5775,5776,5777,5778,5779,5780,5781,5782,5783,5784,1986,1987,1988,1989,1990,1991,1992,1993,1994,1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020,2021,2022,2023,2024,2025,2026,2027,2028,2029,2030,2031,2032,2033,2034,2035,2036,2037,2038,5668,5669,5670,5671,5672,5673,5674,5675,5676,5677,5678,5679))",
        "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)))"
      }
    }
  }
}