SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8af369d513c4dc7ca71d94943070832dc8ae8fc35eb4d6412d37e24b2073eeba' 
  AND token = 'sgnYYXpm5EB7+/8JMIuYmex9Yj+uZTxjp7XDnEXKvYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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