Is this coin still alive?
Yes

 Does it have working pools
I think just solo mine now might be one pool

, exchange,
Only one Crytopia.


 block explorers?
https://www.cryptopia.co.nz/BlockExplorer?coin=MRY

Is it worth to mining it? I think so if there is ever any interest again.  The difficulty is so low you can scoop a lot of coins right now.  Best of luck the ship is without a captain right now.