SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2bf461da7efd445aa90b8df079d526af4b7dd10b780c7a2c15491fbe897f4f2f' 
  AND token = '7hO4pO6/HqtpyKwYEsEtQgpxWeBBZ/A6eAhsU7qvGYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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