Employment Law Questions? Ask an Employment Lawyer.
Well, whether or not you have a claim here depends on your status as an employee.
If you were salaried exempt, then there really is not legally set time frame for the amount you have to work. The sentence "I was salaried for 45 hours" then doesn't make legal sense, because the law doesn't work like that for salaried exempt employees. Time cards can be requested for salaried exempt employees, just to keep track of how much they work, but it's not because the employer is legally limited to 45 hours or any other limitation a week. Suggesting that you take the time off, as comp time, is quite common so that also doesn't suggest that you were not salaried exempt.
If you were salaried non-exempt, and you were being paid overtime for those 5 hours you worked over 40, then you should have received overtime for all the hours. You'd have a claim then.
So again, this all hinges on your employment status. The only way to know that for sure is to file a complaint with the state level Department of Labor, claiming unpaid overtime owed due to your employment status. The employer would then have to prove that your employment was salaried exempt and that the job itself was appropriate for that classification. If they can though, you wouldn't be owed any additional payment.