You might could consider disabling the Allow Empty Query Result option and enabling an error view which would capture the pass-through data in the event that no results are returned. Then follow up with a Union snap and mapping as needed.
Something like this:
Hello Chandan,
ServiceNow Query snap with enabled Allow Empty Query Result and in that case, if provided sys_id exists or record matched, showing the original document.
ServiceNow Query snap with enabled Allow Empty Query Result and in that case, if provided sys_id does not exists or record is not matched, showing the original document.
