Featured escape maps change every Tuesday, so I can't give much specific advice. I recommend going for this as soon as you can after it changes. That gives you the best chance of being matched with good players. You should play the map on beginner a few times to learn the path and weapon drops, then jump into the inconceivable queue. As long as you stay ahead of the venom on inconceivable, you should do fine for time. Pick up the cog tags to do even better.
I spent about 10 minutes in the hive and got a time of negative 27 minutes. Gold for the map I did was negative 15 minutes. Performing kills, executions, headshots, etc. earns you extra time. Score cards and modifiers increase the amount of time added for each action.
Also, joining a game in progress won’t get any of the features rewards, including the achievement.