This would not be very straightforward, but you could read server sessions log to identify file usage.
You can get an idea of how to read this file analyzing this qvw:
You could first read this log, then identify usage and choose to update your qvw or not inside script, but since your load is very quick, maybe this approach will not have a good performance
Thanks to all for the suggestions.
Yes, the overhead of checking to see if someone is using the document is much higher than simply allowing the document to reload on a 5 minute schedule. In fact, the log shows 3 seconds to connect to the database, read the records, and complete the reload. Another 5-6 seconds are used to start the task, distribute the document, and close out the task.