I have laid one, gotten others out on dates, and in other cases built a lot of connection and either kicked myself for not pulling the trigger or been cockblocked by other customers arriving at the wrong moment, or bosses, colleagues etc. It can definitely be done. The question is how.
There are several keys to success IMO. The first is that first impressions are absolutely VITAL. There's no point giving your order all business-as-usual and then starting to put the moves on her. You're well behind the starting line at that point and you'll have to work hard to catch up.
So, snap her out of autopilot with a genuine compliment (her makeup is a good one to choose) and tell her she looks INCREDIBLE and get introduced and get the basic facts (her nationality, how long she's been working there, her schedule etc) before you order, as this will help you a lot later on.
The next thing to focus on is CONNECTION BUILDING like "this guy really GETS me". Either sit near the counter and chat with her there, or whenever she comes to your table lead in with "so you were telling me that ..." or crack a joke/tease her/etc. But find out as much as you can about her, her passions etc, ask a lot of WHY questions, RELATE RELATE RELATE, qualify too.
The final thing is PULL THE TRIGGER. Basically all the planets have to align for you to get a date. There has to be no cockblocks or distractions for the necessary time period in which you have to reach a high point and then ask her out, and you must have built sufficient comfort. You will have to accept that in many cases this simply never happens and you must treat the interaction as practice or simply being social (or long game which is fun but not promising IMO). But if the opportunity presents... SMASH it, do not hesitate as there more than likely won't be another one! Lost so many like this.
AND you must be maximally discreet, her boss could be watching from the kitchen etc. In nearly all cases that I have got dates it was by memorizing her contact, so this is a necessary skill to practice IMO, and you must NEVER pull out your phone in her workplace, if memorizing isn't an option then one of you can write it down on paper but this gives her far more opportunities for hesitation and is hard to do at a high point in the conversation. I HAVE had dates like this though.
As one last tip I suggest to keep your cool, it takes strong nerves to manage a seduction in what is basically a hostile environment and be successful, the temptation is whenever she goes away you over-invest mentally and over-think shit and say something weird when she comes back. Just be calm and detached and outcome-independent, have fun and you're golden

Happy hunting
Ray