(a) Whoever in exchange for either a loan of money or other property knowingly contracts for, charges, takes or receives, directly or indirectly, interest and expenses the aggregate of which exceeds an amount greater than twenty per centum per annum upon the sum loaned or the equivalent rate for a longer or shorter period, shall be guilty of criminal usury and shall be punished by imprisonment in the state prison for not more than ten years or by a fine of not more than ten thousand dollars, or by