Is it illegal for a small business owner in Arizona to not pay overtime if I work more then 40 hours a week?

My boss (a small business owner in Scottsdale) fired me because I didnt want to work 12 hour days. I told him that I didnt want to work that much because I would end up working more then 40 hours this week and he doesnt pay OT. He specifically told me that he wont pay overtime.