SELECT 
  cscart_product_prices.product_id, 
  COALESCE(
    cscart_master_products_storefront_min_price.price, 
    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 
  LEFT JOIN cscart_master_products_storefront_min_price ON cscart_master_products_storefront_min_price.product_id = cscart_product_prices.product_id 
  AND cscart_master_products_storefront_min_price.storefront_id = 1 
WHERE 
  cscart_product_prices.product_id IN (
    17, 180, 18, 16, 4, 5, 23, 24, 1, 22, 149, 
    190, 189, 3438, 3439, 3440, 3441, 121590, 
    136148, 156245, 169350, 125861, 122330, 
    152282, 146567, 139654, 133778, 149640, 
    159133, 146242, 165619, 121896, 143574, 
    121541, 161803, 151867, 130403, 144684, 
    120464, 144963, 125358, 157738, 154235, 
    137235, 157361, 133193, 157759, 159140, 
    166388, 176206, 135170, 128666, 120703, 
    142104, 162657, 128639, 137145, 145590, 
    160493, 159086, 144380, 153320, 171492, 
    156206
  ) 
  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 0.02122

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.263454463,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_prices",
          "access_type": "range",
          "possible_keys": [
            "usergroup",
            "product_id",
            "lower_limit",
            "usergroup_id",
            "wdbi_product_id_lower_limit_usergroup_id_price_eff1727beeef",
            "wdbi_usergroup_id_lower_limit_product_id_92b7e8f6a250",
            "wdbi_product_id_lower_limit_usergroup_id_price_perc_3b2301d551d0",
            "wdbi_lower_limit_usergroup_id_product_id_b93629431718"
          ],
          "key": "usergroup",
          "key_length": "9",
          "used_key_parts": ["product_id", "usergroup_id", "lower_limit"],
          "loops": 1,
          "rows": 128,
          "cost": 0.22335624,
          "filtered": 20,
          "attached_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.product_id in (17,180,18,16,4,5,23,24,1,22,149,190,189,3438,3439,3440,3441,121590,136148,156245,169350,125861,122330,152282,146567,139654,133778,149640,159133,146242,165619,121896,143574,121541,161803,151867,130403,144684,120464,144963,125358,157738,154235,137235,157361,133193,157759,159140,166388,176206,135170,128666,120703,142104,162657,128639,137145,145590,160493,159086,144380,153320,171492,156206) and cscart_product_prices.usergroup_id in (0,1)"
        }
      },
      {
        "table": {
          "table_name": "cscart_master_products_storefront_min_price",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "8",
          "used_key_parts": ["product_id", "storefront_id"],
          "ref": [
            "u985510652_ecartify_abhi.cscart_product_prices.product_id",
            "const"
          ],
          "loops": 25.6,
          "rows": 1,
          "cost": 0.023716864,
          "filtered": 100,
          "attached_condition": "trigcond(cscart_master_products_storefront_min_price.product_id = cscart_product_prices.product_id)"
        }
      }
    ]
  }
}