It is possible to check as follows if you use Accel Documents 2016 Summer or later versions.
・Search all documents under the target drawers/folders from the search tab of the document management screen
All documents can be searched by selecting a name attribute, set “There are values”, and selecting document in the search target type.
・Select the attribute [Locked user]and [Select lock date and time] and output it to CSV
-- Target -------------------------------------------------------------------------
iAP/Accel Applications/Accel Documents/2016 Summer or later
--------------------------------------------------------------------------------
FAQID:1083