Thanks for your question.
It depends on your age when convicted.
Spent after 2 years if 17 or under when convicted. Otherwise spent after 4 years.
Spent convictions do not show on a basic crb check but they do on standard and enhanced searches.
I hope this helps.
If you were convicted in 1993 then the convictions will be spent.
To say you have unspent convictions means they are recent which they are not.