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 (
    8007, 7724, 7897, 7952, 7959, 7972, 7974, 
    8009, 8010, 7948, 7949, 7953, 7962, 
    7964, 7968, 8005, 8013, 7231, 7249, 
    7391, 7947, 7955, 7957, 7958, 7975, 
    7992, 7024, 7355, 7893, 7954, 7970, 
    7977, 7196, 7350, 8080, 7227, 7324, 
    7500, 7956, 8006, 7022, 7080, 7191, 
    7250, 7320, 7340, 7352, 7888, 8110, 
    8192, 8364, 7021, 7192, 7256, 7506, 
    7850, 7230, 7319, 7343, 7386, 7900, 
    8214, 7189, 7226, 7348, 7356, 7390, 
    7965, 7232, 7237, 7344, 7383, 7389, 
    7887, 7894, 8207, 9909, 7193, 7262, 
    8069
  ) 
  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 0.00227

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "56.01"
    },
    "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": 80,
        "rows_produced_per_join": 15,
        "filtered": "19.99",
        "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`product_id` in (8007,7724,7897,7952,7959,7972,7974,8009,8010,7948,7949,7953,7962,7964,7968,8005,8013,7231,7249,7391,7947,7955,7957,7958,7975,7992,7024,7355,7893,7954,7970,7977,7196,7350,8080,7227,7324,7500,7956,8006,7022,7080,7191,7250,7320,7340,7352,7888,8110,8192,8364,7021,7192,7256,7506,7850,7230,7319,7343,7386,7900,8214,7189,7226,7348,7356,7390,7965,7232,7237,7344,7383,7389,7887,7894,8207,9909,7193,7262,8069))",
        "cost_info": {
          "read_cost": "54.41",
          "eval_cost": "1.60",
          "prefix_cost": "56.01",
          "data_read_per_join": "383"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`lower_limit` = 1) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}