SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b7df8d68d5458550ed08ec0809079c61303e8fe3698700216c7939c2dd072cf' 
  AND token = 'xdGiE8AHen8to7DfqXhyGjWwiJCkgWBbrQtUFxfjOPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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