Can you be forced to work overtime in KY or is it against the law to make someone work over 40 hours a week?

Well, they can't force you to work overtime. But there is no law that says they can't require overtime and no law that says they can't discipline you, up to and including termination, if you cannot or will not work it.

http://www.labor.ky.gov/ows/employmentstandards/faq/

There is no state where an employer is forbidden to require an employee to work over 40 hours per week. The ONLY legal significance that 40 hours has, is that it is at that point that a non-exempt employee is due overtime.