Upvote:4
According to EasyJet Plus' website, it seems that the EasyJet Plus card itself does not grant you access to Fast Track security, instead it is a valid EasyJet Plus card membership number added to your booking that grants you access:
Fast Track will be added to your boarding pass if the airport you are flying from is part of the programme. You must add a valid easyJet Plus card membership number to your booking which will automatically display the Fast Track symbol on your boarding pass.
[...]
Once you are at the airport Follow the signs to Fast Track security and show the security agent your boarding pass to enter. If the Fast Track security gate is an automated system, you can scan your boarding pass barcode to enter. Please note that you cannot use your easyJet Plus card for Fast Track entry.
(Emphasis mine)