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 (
    7401, 7394, 7462, 7420, 7400, 7441, 7035, 
    7410, 7393, 7402, 7409, 7404, 7396, 
    7395, 7403, 7405, 7034, 7399, 7407, 
    7447, 7408, 7434, 7448, 7360, 7449, 
    7458, 7421, 7424, 7433, 7425, 7436, 
    7440, 7444, 7445, 7457, 7459, 7460, 
    7428, 7442, 7461, 7463, 7426, 7432, 
    7453, 7398, 7451, 7452, 7397, 7450, 
    7454, 7455, 7456, 7358
  ) 
  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 0.00237

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "37.11"
    },
    "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": 53,
        "rows_produced_per_join": 10,
        "filtered": "19.99",
        "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`product_id` in (7401,7394,7462,7420,7400,7441,7035,7410,7393,7402,7409,7404,7396,7395,7403,7405,7034,7399,7407,7447,7408,7434,7448,7360,7449,7458,7421,7424,7433,7425,7436,7440,7444,7445,7457,7459,7460,7428,7442,7461,7463,7426,7432,7453,7398,7451,7452,7397,7450,7454,7455,7456,7358))",
        "cost_info": {
          "read_cost": "36.05",
          "eval_cost": "1.06",
          "prefix_cost": "37.11",
          "data_read_per_join": "254"
        },
        "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)))"
      }
    }
  }
}