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 (
    2698, 2340, 3834, 3306, 5848, 2352, 2431, 
    5114, 2922, 5798, 5801, 5829, 3301, 
    5852, 5928, 5847, 2341, 5794, 2702, 
    3147, 3520, 3529, 3146, 3809, 3148, 
    3215, 3213, 3552, 3149, 3157, 5791, 
    3845, 3150, 2228, 3664, 2230, 2655, 
    5890, 2226, 3843, 3840, 5891, 2719, 
    5111, 3385, 3831, 3289, 3382, 3222, 
    3522, 5804, 5113, 3537, 3387, 3388, 
    3528, 3819, 3309, 2918, 3384, 3532, 
    2720, 3807, 2727, 2229, 3550, 3220, 
    5107, 6112, 2429, 3805, 3524, 2921, 
    3668, 3702, 3670, 3684, 3682, 3230, 
    3303
  ) 
  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 0.00210

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 (2698,2340,3834,3306,5848,2352,2431,5114,2922,5798,5801,5829,3301,5852,5928,5847,2341,5794,2702,3147,3520,3529,3146,3809,3148,3215,3213,3552,3149,3157,5791,3845,3150,2228,3664,2230,2655,5890,2226,3843,3840,5891,2719,5111,3385,3831,3289,3382,3222,3522,5804,5113,3537,3387,3388,3528,3819,3309,2918,3384,3532,2720,3807,2727,2229,3550,3220,5107,6112,2429,3805,3524,2921,3668,3702,3670,3684,3682,3230,3303))",
        "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)))"
      }
    }
  }
}