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 (
    2048, 2049, 2050, 2051, 2052, 2053, 2054, 
    2055, 2056, 2057, 2058, 2059, 2060, 
    2061, 2062, 2063, 2064, 2065, 2066, 
    2067, 2068, 2069, 2070, 2071, 2072, 
    2073, 2074, 2075, 2076, 2077, 2078, 
    2079, 2080, 2081, 2082, 2083, 2084, 
    2085, 2086, 2087, 2088, 2089, 2090, 
    2091, 2092, 2093, 2094, 2095, 2096, 
    2097, 2098, 2099, 2100, 2101, 5722, 
    5723, 5724, 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
  ) 
  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 0.00121

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "67.66"
    },
    "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": 97,
        "rows_produced_per_join": 19,
        "filtered": "20.00",
        "index_condition": "(`gaseus`.`cscart_product_prices`.`product_id` in (2048,2049,2050,2051,2052,2053,2054,2055,2056,2057,2058,2059,2060,2061,2062,2063,2064,2065,2066,2067,2068,2069,2070,2071,2072,2073,2074,2075,2076,2077,2078,2079,2080,2081,2082,2083,2084,2085,2086,2087,2088,2089,2090,2091,2092,2093,2094,2095,2096,2097,2098,2099,2100,2101,5722,5723,5724,5725,5726,5727,5728,5729,5730,5731,5732,5733,5734,5735,5736,5737,5738,5739,5740,5741,5742,5743,5744,5745,5746,5747,5748,5749,5750,5751,5752,5753,5754,5755,5756,5757,5758,5759,5760,5761,5762,5763))",
        "cost_info": {
          "read_cost": "65.72",
          "eval_cost": "1.94",
          "prefix_cost": "67.66",
          "data_read_per_join": "465"
        },
        "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)))"
      }
    }
  }
}