Table/Column Character Encoding and Indexes Does table/column character encoding have any impact on how the MySQL optimizer chooses join indexes?

I have a table that have the same columns and indexes on two servers, one server does a eq_ref under type and the other does ALL

Only difference I see is the character encoding. Could that be the cause query not using an index? In the database that isn't performing, one table is latin1 and the joining table is utf8.

1st Server

# id, select_type, table, partitions, type, possible_keys, key, key_len, ref, rows, filtered, Extra
1, PRIMARY, tx, , ALL, , , , , 234587263, 100.00, Using where; Using join buffer (Block Nested Loop)

2nd Server

# id, select_type, table, partitions, type, possible_keys, key, key_len, ref, rows, filtered, Extra
1, PRIMARY, tx, , eq_ref, PRIMARY, PRIMARY, 198, db1.log.hash, 1, 100.00,
I found my answer here.  Quick answer is - they need to be the same collation/encoding to use an index.
https://stackoverflow.com/questions/2266241/utf-8-vs-latin1-mysql-indexes-not-used-on-utf-8