How can I check if panelizer is in use?

Hi all,
I took over an older Drupal project where Panelizer module is installed and enabled. Now I am wondering how I can figure out if panelizer is realy used.
I find a database table "node__panelizer". This table is empty. Does it mean that panelizer is not in use? Or what should I check to find out if I really need the module to stay installed?