If you are not logged in to your lockrMail account on the Chrome extension, the lock will still populate in email registration fields across the web. When you click the lock, a box will pop-up urging you to hit command+shift+L in order to open the extension and sign-in to your account.
If command+shift+L is not working for you, you may have a conflicting shortcut already set with one of your other extensions. To change this, click the puzzle piece in the top right hand corner of your Google Chrome browser and select ‘Manage extensions.’ From the next screen, select the three bars in the top left hand corner and select ‘Keyboard Shortcuts.’ From that page, you can either (i) change the shortcut for the extension that is already using command+shift+L (i.e. change this to command+shift+P), or you can (ii) change the shortcut key for the lockrMail extension. Be sure to hit “Update” at the top of the page to save your changes.