Regular Expressions \w character class and equals sign

I am creating a regular expression to match the string

@servername:port:databasename

and through https://regex101.com/ I came up with

\@(((\w+.*-*)+)?\w+)(:\d+)(:\w+)

which matches

e.g. @CORA-PC:1111:databasename or @111.111.1.111:111:databasename

However when I use this regular expression to pattern match in my java code the String @CORA-PC:1111:database=name is also matched.

Why is \w matching the = equals sign? I also tried [0-9a-zA-Z] but it also matched the = equals sign?

Can anyone help me with this? Thanks!