I must refer you to pilotmike's earlier post from 30th Dec 2016.
ramprat101uk:
You are NOT obliged to declare a spent conviction, and even if they phrase it "Have you ever been convicted...." you are allowed to answer NO on the basis that they are only allowed to ask "Do you have any unspent convictions". So, DON'T declare it as it won't help you.
Similarly, it will not show on the Basic Disclosure you are required to provide., which I'm sure you already know, because you must already have an airside pass.
As for producing your licence, yes they will know then, so you need to show them you are responsible, have learned from your mistakes etc. Find a way to turn it into a positive.