SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '022f35dbfcebadbcb458bb795bcdd8493b2b12bf950ad93ae14203be9cd64dbf' 
  AND token = 'Y4VdJh8sQQWVXGdOt9hPSn6HgPfielfK5a2DjTxGa7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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