SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '69e065728c639cbcb43da8fcc9846cff2dcd4e724b6d0260446738de7aa8c217' 
  AND token = 'uVr6FDUbWtAxEtCZKfrSCSBpFxzBjBIUObvFOjOn3NA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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