Mo. Rev. Stat. § 521.590: Proceedings to avoid judgments on constructive notice — when defendant has two years to plead.

In cases where judgment is rendered against the defendant, upon publication of notice, without service of a summons or his appearance to the action, he shall be allowed two years, and no longer, from the date of the judgment, to appear and disprove or avoid the debt or damages adjudged against him, or any part thereof.