Question:
Answer:
Yes, it is still valid.
All that is required for a valid baptism is proper intent on the part of the minister, proper matter and form (water and the Trinitarian formula), and the recipient must not to be opposed to the baptism. In the case of infant baptism, obviously the recipient cannot be opposed to the baptism; therefore, as long as the baptizing minister intends to properly baptize and uses proper matter and form, it is valid.
A baptism in which the sponsors are not baptized is highly illicit. The sponsors are supposed to be baptized (canon 874), but the status of the sponsors does not affect the validity of the baptism.
As far as the parents are concerned, it is not absolutely required that they even be Catholic. All that canon law requires is that the parents be willing to raise the child as a Catholic (canon 868). However, this affects only whether the baptism is licit. It does not affect the validity of the baptism.