SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '450048d069d2ec995ace26046547e8946c26022713f18a5a61d63b080e12591f' 
  AND token = '1bf0cxnft3mmneVKZw5UXzwhB595WXhZZI1Ua0AIxVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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