SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d4120842ac3062365e8c59e33cda848d0563a1736ad9fed3c979d95f487ab63' 
  AND token = 'ivfOdtMmwptYxYG5aFgElpl5UwpeN2ZJf03GBlT3FAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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