Is it ok to use crucial and corsair as a pair

yes you can,if your laptop compatible with 667mhz ram any 667mhz RAM will work fine even they are not from the same manufacturer.

At least in theory. In real life, some combinations can be quirky.

It's fine, if there some problems try swapping their (slot) position .............

RAM issues usually happen when mixing RAM of different frequency and latency but those tow RAM sticks have the same frequency (667) and latency(CL5) ,so i think both of them should be 100% compatible @dual channel mode .