SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '475649846405c924f50ddbe7a661ae1d89d5fa2178ee0a15451e6ddbbce81adf' 
  AND token = 'KJ/sFKPpDhUXkieiY7KcTE0lvMNsO76Z21FQEov8FPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00095

JSON explain

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