Mo. Rev. Stat. § 141.121

Any provisions of this chapter to the contrary notwithstanding, the owner of any parcel of real property against which a judgment has been rendered shall not have the right to redeem such property from said judgment if at the time of judgment such property is assessed as residential property and the judgment finds the property has been vacant for a period of not less than six months prior to the judgment. After a judgment as provided for in this section becomes final, a sale under execution of the judgment shall be immediately held as provided under the applicable provisions of this chapter.