Is there a scriptural basis (preferably in Doctrine & Covenants) for the priesthood being restricted to men (at least on this earth)?
If not, what is the explanation for this practice?
Not explicitly, that being said, there are a variety of scriptures that indicate that men are to be ordained to the priesthood, rather than women.
There are no scriptures where it speaks of the priesthood in terms of daughters or mothers. The Priesthood has always been a Patriarchal order, even in the beginning with Adam.
“These are the names of the sons of Aaron, the priests which were anointed, whom he consecrated to minister in the priest’s office.”
“And thou shalt appoint Aaron and his sons, and they shall wait on their priest’s office…”
“The duty of the elders, priests, teachers, deacons, and members of the church of Christ—An apostle is an elder, and it is his calling to baptize;”
“And he may also ordain other priests, teachers, and deacons.
“And he is to take the lead of meetings when there is no elder present;”
It also must be noted that all interactions related to the priesthood were males. Christ himself, Adam Melchizedek, Abraham, Noah, Elijah, Elisha, Moses, Aaron, Peter, James, and John, John the Baptist… All told, not a single reference to women when the priesthood was explicitly given or received.
I'm not aware of anywhere in Scripture where it explicitly says something like "only men can be ordained" or "women can't be ordained". However, I am aware of a passage that may indirectly answer the question.
In Alma 13, Alma is explaining the Priesthood and foreordination to the lawyer, Zeezrom. Alma 13:2 says:
"And those priests were ordained after the order of his Son, in a manner that thereby the people might know in what manner to look forward to his Son for redemption."
This verse and the ones surrounding it can lead to some deeper questions. However, one of the simple messages of this verse is that one of the purposes of ordination to the priesthood is to help us know who our Redeemer is.
If ordination to the Priesthood is meant to help us know who our Redeemer is, and if Jesus Christ is male (or was going to be in mortal life), then among many other traits it seems to me that it would be significant for the people being ordained to be male.
Males aren't the only sex with access to Priesthood power, and ordination isn't the only way to get access to that power. However, ordination into this particular Priesthood order that uses Priesthood power has specific purposes - one of which (according to Alma) is to help people know who our Redeemer is. And among the many, many things that Jesus Christ is, He's male.