Find the closest bar, when searching for a drink
set @x = 15;
set @y = 25;

select sqrt(pow(b.lat-@y,2) + pow(b.lng-@x,2)) as distance,  b.name, d.name
from `drinks` d
 join `drink__bars` db on d.id = db.drink_id
 join  `bars` b on b.id = db.bar_id
where d.`name` = 'Beer'
order by distance asc;


Full sqlfiddle, with some data. Use your preferred distance function to replace the plain one I used.

I would recommend against having Id on many-to-many relations. And prefer NOT NULL always, unless you have a very strong case to allow NULLs (you don't).