They should have filed a case against you within one year's time after they filed this lien affidavit, and if they won the case. Then they will have a judgement against you and put a mechenical lien on your property.
In your case, you should go to county court to find out if you can request removal of this lien affidavit, since 2 years have passed, and they have not filed a case against you.
Without court judgement, this lien should not be validated.