If you were scheduled for 6 hours at my store (the # of hours to hit compliance) you would take a meal, so I don't see why this is an issue. Otherwise the closest shift was 5.50 hours, giving 30 minutes to get out of there (plenty).
If your store tells you NOT to take a Meal for a 6 hour shift, then you better communicate with the LOD that you'll need to leave at least 15 minutes early so you don't hit compliance. I've never seen an LOD tell someone to not take a meal for a 6 hour shift though. Honestly I've never seen that many 6 hour shifts scheduled, usually 6.50 hours or more.