MYSQL distinct random join query

I have two tables

albums      fotos
------      -----
id          id
titulo      url
            fk_album

I would like to know how I can select form all albums that are not empty random photos... and must be distinct... For example:

albums          fotos
------          ------
1 A             1 my_url_1 2
2 B             2 my_url_2 2 
3 C             3 my_url_3 1
4 D             4 my_url_4 2
5 E             5 my_url_5 3
                6 my_url_6 3

I want results like these: (distinct, random & join)

result0 -> 
       albums.id     -> 2
       albums.titulo -> B
       fotos.url     -> my_url_2 (this must be random)
result1 -> 
       albums.id     -> 3
       albums.titulo -> C
       fotos.url     -> my_url_6 (this must be random)
result2 -> 
       albums.id     -> 1
       albums.titulo -> A
       fotos.url     -> my_url_3 (the album only have this foto url)

I have tried many things but actually I can only get the distinct albums with photos but without random values it.