I've been using MySQL and Access for quite some time. MySQL hass but recently added data integrity (4.0.2 I do believe), and that's not by default, you have to use InnoDB tables... for tiny apps Access is much more of a RAD, even if bloated with MS olde VBA document object model, even if again prone to spaghetti development of code and GUIs sitting atop the aging Jet engine.
That being said, I must say however that Access has nicer functions of formatting data and easier time to running app, not to talk about almost instant prototyping.
I developed myself a legacy framework that calls any old ODBC compliant db and serves XML as output, which is later usable through XSL. I must say that Access is faster to get with, especially when using wizards to spit out Jet SQL code with joins for the db newbie at an impressing rate (there are a plethora of other tools to do that but since you've mentioned MySQL CC... let's stick to what each package offers). Also, the almost-diagramming tool :-)) included with MSAccess is a nice to have add-on.
On the other side, if we're talking about multi-user, locking and more recently, transactions, that ends the comparison bluntly - Access technical k.o. Since any decent app does more than just perpetual reading by more than one user on more than one machine, I guess this is where MySQL just starts to make a difference. From here, scalability, performance and so on... with only one comparison term left, it's not worth benchmarking it anymore. As usually, the business need makes the decision.