(1) Any person who knowingly charges, takes, or receives any money or other property as a loan finance charge where the charge exceeds an annual percentage rate of forty-five percent or the equivalent for a longer or shorter period commits the crime of criminal usury, which is a class 6 felony.

(2) It is an affirmative defense to criminal usury for a person, or his agent or assignee, who charges, takes, or receives money or property as a loan finance charge in excess of an annual percentage rate of forty-five percent in either of the following circumstances:

(a) That at the time of making the loan finance charge it could not have been determined by a mathematical computation that the annual percentage rate would exceed an annual percentage rate of forty-five percent;

(b) That the loan finance charge was not in excess of an annual percentage rate of forty-five percent when the rate of the finance charge was calculated on the unpaid balance of the debt on the assumption that the debt is to be paid according to its terms and is not paid before the end of the agreed term.

(3) The affirmative defenses referred to in subsection (2) of this section shall only apply when the provisions relating to the loan finance charge are set forth in a written agreement signed by all the parties and such written agreement is submitted to the court and the district attorney at least ten days prior to trial.

(4) This section shall not apply to:

(a) Charges and fees permitted by articles 1 to 6 of title 5, C.R.S., or charges and fees that are similar to such charges and fees and are specifically authorized by law;

(b) Credit card charges and fees not exceeding those permitted for consumer transactions under articles 1 to 6 of title 5, C.R.S., when imposed upon or collected from a person or in a transaction not subject to said provisions;

(c) A reverse mortgage as defined in section 11-38-102, C.R.S.; and

(d) Additional interest charges permitted by section 5-12-107 (3), C.R.S.