Mo. Rev. Stat. § 382.640

If any provision of sections 382.600 to 382.640 or the application thereof to any person or circumstance is held invalid under the Constitution of the United States or the Constitution of the state of Missouri, such determination shall not affect the provisions or applications of sections 382.600 to 382.640, which may be given effect without the invalid provision or application, and to that end the provisions of sections 382.600 to 382.640, with the exception of section 382.620, are severable.