Edit Locks on tickets are, unfortunately, not stored in the database. FootPrints Service Core writes a temp file in the footprints\temp directory to track the workspace number and ticket number that is currently being edited. For example, if I was editing ticket 1234 in workspace 1, the file in footprints\temp would be named EditLock.1.1234.txt. Inside there will be the FootPrints user ID of the user editing the ticket.
That being said, creating a homepage dashboard to look for specific files on the FootPrints Service Core server is beyond my knowledge. If you could write some program that would scan the footprints\temp directory for any EditLock.*.txt files, you could have it output the results in a simple HTML file that can then be called up as a custom dashboard component.
Hope that gets you started in the right direction.