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 (
    1, 228, 8, 9, 5290, 10, 8483, 2892, 71, 
    2896, 2902, 4, 2359, 1532, 2906, 5271, 
    6340, 8499, 8502, 5851, 8501, 4974, 
    5277, 2459, 5640, 5284, 5376, 5287, 
    5281, 5397, 4995, 5270, 2901, 5278, 
    5187, 5549, 5235, 1528, 2776, 2432, 
    2771, 4992, 5661, 2774, 5207, 2455, 
    5737, 6385, 5186, 1517, 5008, 5272, 
    4991, 2438, 5276, 8498, 5660, 7624, 
    8484, 8497, 5285, 5346, 2812, 5728, 
    7608, 5879, 2250, 8485, 1538, 5265, 
    8488, 8486, 8492, 2899, 5288, 8487, 
    5523, 7614, 5666, 6823
  ) 
  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 0.00166

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 (1,228,8,9,5290,10,8483,2892,71,2896,2902,4,2359,1532,2906,5271,6340,8499,8502,5851,8501,4974,5277,2459,5640,5284,5376,5287,5281,5397,4995,5270,2901,5278,5187,5549,5235,1528,2776,2432,2771,4992,5661,2774,5207,2455,5737,6385,5186,1517,5008,5272,4991,2438,5276,8498,5660,7624,8484,8497,5285,5346,2812,5728,7608,5879,2250,8485,1538,5265,8488,8486,8492,2899,5288,8487,5523,7614,5666,6823))",
        "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)))"
      }
    }
  }
}