Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71add1a8b50a7927ee889dcb25fcbf9a212a441f58049d960b5c884fab1a56a4' 
  AND token = 'E97XbbLD3TPx/PyYJVJvE7MNJkEdAfzVLdj0r9daFCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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