SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa997b57ce8756434fbd5a6881db68475c3c84a4b72dbcf303674ee277bade86' 
  AND token = 'tD9q6YhxGXhpV11vbtHbOHmnjqXfgnTHwiFk+33wdd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}