Determining if Swift dictionary contains key and obtaining any of its values

I am currently using the following (clumsy) pieces of code for determining if a (non-empty) Swift dictionary contains a given key and for obtaining one (any) value from the same dictionary.

How can one put this more elegantly in Swift?

// excerpt from method that determines if dict contains key
if let _ = dict[key] {
    return true
}
else {
    return false
}

// excerpt from method that obtains first value from dict
for (_, value) in dict {
    return value
}