If you have access to a PC with a floppy drive, copy the content from your key disk on an USB stick. It's just a single file that you can unzip into your A5 folder for unlocking it.

As to the A6 version, please send an email to the support address listed on the Support FAQ page. They'll have a bunch of advices how to upgrade to A7 despite a lost key, and how to reconstruct a lost key.