Active Directory - How do you generate a DirSync cookie without crawling to completion?

I have used an Ldap query to fetch all objectClass=group and objectClass=user from Active Directory.

Now I want to use DirSync to get all changes since then.

DirSync is described at https://support.microsoft.com/en-us/help/891995/how-to-poll-for-object-attribute-changes-in-active-directory-on-window

But the problem is I can only really figure out how to generate a cookie after doing an entire crawl of the entire contents. And that includes deletes which is like 5,000,000 items in my case. Takes some time to get the initial cookie.

Is there a way to generate a token for "now" in a faster way?