I have good news and bad news: I'm a criminal defense lawyer in AR, but I have no experience in dealing with the interplay between Arkansas criminal law and federal criminal statutes and rules. I've never prosecuted or defended a federal criminal case, so I've never needed to go down that rabbit hole.
Anyway, as others have noted, a no-knock warrant is just what it sounds like: a warrant allowing law enforcement to execute the warrant without knocking & announcing their presence. (And just in case someone runs across them, we also have a line of cases in Arkansas that we call the "knock and talk" cases. They're not relevant here, because they're not warrant cases. They deal with the police just walking up to a residence, knocking and talking to whoever answers.) Generally speaking, no-knock warrants are disfavored in Arkansas, but police seek them in cases where there is some specific danger, either related to confrontation with the police, or destruction of evidence, or something along those lines.
Also worth noting, but not especially relevant here, is the fact that it was issued as a daytime warrant. Like no-knock warrants, nighttime warrants are disfavored and (should) only be issued when there is a specific, articulated reason that the warrant cannot be served during the day. (When the pdf from the link opens on my computer, the boxes to be checked for that are on p. 37.) I say it isn't relevant here, just because this one was issued as a daytime warrant, and appears to have been executed during the daytime.
Finally, I notice on p. 2 of my pdf that the box for "a person to be arrested or a person who is unlawfully restrained" is not checked. IOW, if LE were looking to arrest Malinowski right then and there, this warrant didn't give them that authority.