We have found one software suitable in our database for this conversion.
key to docx conversion is often searched by users looking for a way to convert old iWorks Keynote presentations (.key) to MS Word, or at least the texts from these files.
The best way how to approach this nowadays, is to use the iCloud version of iWorks, import the presentation there and recover or export any of its elements as MS Word document.
Updated: March 28, 2023
KEY
Files with key extension can be often found as presentations saved in latest versions of Apple (iWork) Keynote, a professional presentation tool for Mac OS X, macOS and iOS.
DOCX
Files with docx file extension are documents written and saved using Microsoft Word word processor edition 2007 or later. DOCX format replaced the previously used DOC format, moving from binary files to Open XML schema-based documents. They are supported in almost every modern word-processing tools.