It is lawful for a party to loan money in this state by reserving or discounting interest upon commercial paper, mortgages, or other securities for any period authorized by a rule or regulation of the Federal Housing Administration or its successor or for a period of at least thirty-six (36) months, whichever is greater, at any rate of interest agreed upon by the parties not to exceed the applicable rate of interest, if any, prescribed by Arkansas Constitution, Amendment 89, whether the papers or securities for principal or interest are payable in this state, or in any other state, territory, kingdom, or country.