Don't Expect Massively Faster Cryptokey Earn Rate
With the introduction of new Black Ops 3 weapons available only through Supply Drops many users worried that Treyarch and Activision slowed the earn rate of Cryptokeys to push users to buy Call of Duty Points.
User rdtTocher96 on Reddit shares stats about the Cryptokey earn rate, comparing them to stats collected last year and found that while there are some changes the earn rate is not slower than it was.
No matter what game mode you play, the Cryptokey earn rate is very similar, with the only major difference coming when you win a match. The short summary of the information from rdtTocher96 is, "No mode is better than another for earning crypto keys. Based off my testing you earn 29.20% of a key every minute of a match you won and 22.37% of a key every minute of a match you lost. If you want more keys play the objective to win the match."
With this in mind, there is a lot of demand for a higher Cryptokey earn rate, but it is unlikely that Treyarch and Activision will enable this in a long term fashion. There is a lot of psychology behind the speed at which you earn these points -- designed to push users to buy the Call of Duty Points.
If anything, you should hope for a March Black Ops 3 Double Cryptokey weekend, which is far more likely.