Prime To-Do List fields can be used in JQL. Below are a few useful examples.

Check if the field has any value (or has none)

The operators IS EMPTY and IS NOT EMPTY can be used to search issues where the field has any value, or none.

Search for issues with a specific entries (checked or not)

The search alias All can be used to search among all the To-Do list entries, regardless if they are checked or not.

Search for issues with a specific entries checked

The search alias Checked can be used to search among the To-Do list entries that are checked.

Search for issues with a specific entries unchecked

The search alias Unchecked can be used to search among the To-Do list entries that are unchecked.