SELECT 
  cscart_payments.*, 
  cscart_payment_descriptions.*, 
  IF (
    ISNULL(cscart_addons.status), 
    "A", 
    cscart_addons.status
  ) AS processor_status, 
  cscart_payment_processors.type AS processor_type, 
  cscart_payment_processors.processor_script AS processor_script, 
  cscart_payment_processors.processor AS processor 
FROM 
  cscart_payments 
  LEFT JOIN cscart_payment_descriptions ON cscart_payment_descriptions.payment_id = cscart_payments.payment_id 
  AND cscart_payment_descriptions.lang_code = 'ru' 
  LEFT JOIN cscart_payment_processors ON cscart_payment_processors.processor_id = cscart_payments.processor_id 
  LEFT JOIN cscart_addons ON cscart_payment_processors.addon = cscart_addons.addon 
  LEFT JOIN cscart_storefronts_payments AS storefronts_payments ON storefronts_payments.payment_id = cscart_payments.payment_id 
WHERE 
  cscart_payments.status = 'A' 
  AND (
    storefronts_payments.storefront_id = 1 
    OR storefronts_payments.storefront_id IS NULL
  ) 
  AND cscart_payment_processors.processor_script IN ('kupivkredit.php') 
HAVING 
  processor_status = 'A' 
ORDER BY 
  cscart_payments.position

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "having_condition": "processor_status = 'A'",
    "table": {
      "table_name": "storefronts_payments",
      "access_type": "system",
      "possible_keys": ["PRIMARY", "idx_storefront_id"],
      "rows": 0,
      "filtered": 0,
      "const_row_not_found": true
    },
    "read_sorted_file": {
      "filesort": {
        "sort_key": "cscart_payments.position",
        "table": {
          "table_name": "cscart_payments",
          "access_type": "ALL",
          "rows": 9,
          "filtered": 100,
          "attached_condition": "cscart_payments.`status` = 'A'"
        }
      }
    },
    "table": {
      "table_name": "cscart_payment_descriptions",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["payment_id", "lang_code"],
      "ref": ["admin_test.cscart_payments.payment_id", "const"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "trigcond(cscart_payment_descriptions.lang_code = 'ru')"
    },
    "table": {
      "table_name": "cscart_payment_processors",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["processor_id"],
      "ref": ["admin_test.cscart_payments.processor_id"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "cscart_payment_processors.processor_script = 'kupivkredit.php'"
    },
    "table": {
      "table_name": "cscart_addons",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "98",
      "used_key_parts": ["addon"],
      "ref": ["admin_test.cscart_payment_processors.addon"],
      "rows": 1,
      "filtered": 100
    }
  }
}