grep lines with two specific characters somewhere in the line

I'm having trouble with extracting certain lines from a file based on whether they have all the required fields.

Original file:

snt:594:Sam N This
bpt:2342:Bob P That
lr:123
wrp:23:Whoever Person
cor:794

Desired output:

snt:594:Sam N This
bpt:2342:Bob P That
wrp:23:Whoever Person

I've searched and I haven't been able to find anything to target only these lines. The only thing I can think of is this but it doesn't work:

grep ":*:" < temp

grep '.*:.*:.*' myFile
OR
nawk -F: 'NF==3' myFile

That's exactly what I was looking for. Thanks!

To understand it better, you are missing . (dot) thats all. Previously you had :* which meant zero or more :.

 grep ":.*:" t1

The above will also work, if the input you had given is as similar as you had given in your 1st post.