Mo. Rev. Stat. § 443.454

The enforcement and servicing of real estate loans secured by mortgage or deed of trust or other security instrument shall be pursuant only to state and federal law and no local law or ordinance may add to, change, delay enforcement, or interfere with any loan agreement, security instrument, mortgage or deed of trust. No local law or ordinance may add, change, or delay any rights or obligations or impose fees or taxes of any kind or require payment of fees to any government contractor related to any real estate loan agreement, mortgage or deed of trust, other security instrument, or affect the enforcement and servicing thereof.