SQL Server hangs on a specific record
If a specific query hangs, it's usually due to blocking. Is it possible that someone else has an active transaction that is affecting this row (or the page or partition it's in)? When you run this query, what does it show in sys.dm_exec_requests for that spid? First run:

SELECT @@SPID;


Make note of the number, then try to run the query. In another window, run the following:

SELECT blocking_session_id, wait_type FROM sys.dm_exec_requests
  WHERE session_id = &lt;SPID from above&gt;;


If a session shows up in blocking_session_id, find out who they are and what they're doing.

SELECT * FROM sys.dm_exec_requests
  WHERE session_id = &lt;blocking_session_id from above&gt;;

DBCC INPUTBUFFER(&lt;that spid&gt;);


You can also check if the database has any old transactions that may be causing an issue:

DBCC OPENTRAN();