I have statements like this that are timing out:
DELETE FROM [table] WHERE [COL] IN ( \'1\', \'2\', \'6\', \'12\', \'24\', \'7\', \'3\', \'5\')
In my case the database statistics had become corrupt. The statement
delete from tablename where col1 = 'v1'
was taking 30 seconds even though there were no matching records but
delete from tablename where col1 = 'rubbish'
ran instantly
running
update statistics tablename
fixed the issue