It seems that there isn't a direct result from the search that outlines the explicit steps for deleting an expired CSRF token from the Prefect database. Given Prefect's security policies and best practices, it's likely that such a task may require a more in-depth understanding of their database management or might involve accessing administrative functionalities of Prefect Cloud or Prefect Server.
Considering the lack of information in the documentation, if you're unable to figure out a way to manage CSRF tokens directly, the recommended step would be to contact Prefect support directly for guidance on this issue. Here's the link to the page where you might find further assistance:
Prefect Blog and
Prefect Security. You can reach out to them via community Slack, booking a time with a product advocate, or emailing
help@prefect.io.