English equivalent of Russian "по кд" meaning "used repeatedly and as soon as possible"

From what I understand, your expression (по кд) is a gaming term, so the word you are looking for is almost certainly “spam”:

Spamming, in the context of video games, refers to the repeated use of the same item or action. For example, "grenade spamming" is the act of a player throwing many grenades in succession into an area. In fighting games, one form of spamming would be to execute the same offensive maneuver or combo so many times in succession that one's opponent does not receive a chance to escape the series of blows.

Usually this is said of actions that have a short cool down (see also button mashing), but it is also used for moves in turn based games, like Pokémon:

[S]mart players will have planned ahead and will know how to avoid overusing the move [Protect]… which, ironically, will allow them to spam it against other players who might not be able to catch a break in between bouts of unbreakable Protect and swift attacks.

Spam is used as both a verb and a noun (and spamming is also a noun/gerund):

While the game [Super Smash Bros.] discourages spamming with stale-move negation, the point of spam is to throw out many attacks to the point where the reduced damage can be made up simply by using the move twice as much

Additionally, spam is used in programming to describe a system that produces output as fast as it can, in particular when it does it enough that it puts strain on (or even takes down) a system that is receiving its output:

How to Limit web requests per second to avoid spamming and denial of service

The closest counterpart in English seems to be "a spree". "Kill spree", "death spree", etc. The slang flavor is missing, of course, but in Russian the phrase is used outside of gaming a lot nowadays - especially by younger people - to mean "repeatedly", "easily", "quickly".