В MySQL това работи
SELECT foobar.description
FROM foobar
ORDER BY foobar.description <> 'fff',
foobar.description ASC
Но обикновено можете да използвате и case
SELECT foobar.description
FROM foobar
ORDER BY case when foobar.description = 'fff' then 1 else 2 end,
foobar.description ASC