Selecting default value query returns blank
I think you're going about this all wrong. 

You want to wrap IFNULL around the actual field.

SELECT IFNULL(as_title, 'lorem ipsum') FROM all_scheduled_messages WHERE id = 1 LIMIT 1;


However, if you're returning a blank, rather than a NULL from your query, IFNULL will not work. You'll need to NULL the value first:

SELECT IFNULL(NULLIF(as_title, ''), 'lorem ipsum') FROM all_scheduled_messages WHERE id = 1 LIMIT 1;