Legal Question in Employment Law in Kentucky

No. Persons without valid driver's licenses are not a protected class under the law.

In order to sue for employment discrimination, you must have been discriminated against because you are a member of a protected classification of persons, for instance, because of your race or your gender. "Discrimination" is not when you are treated unfairly by your employer because they bust you for doing something that a few other of your co-workers do, i.e. driving cars in the scope of your employment without a driver's license. Unless of course, they are busting you because they want to get rid of you due to your race, gender, nationality, religion, disability, etc., etc. Employment is at-will, meaning unless there is an employment contract in place that specifically says otherwise, an employer can fire you for whatever reason they feel like, fair or not, unless it is an illegal reason under the law (i.e. discrimination, etc.)

I would suggest taking affirmative steps to obtaining a valid Kentucky driver's license and finding new employment. You should never have been operating a motor vehicle without a valid driver's license. Doing so is a criminal offense.