create_tables with safe=True doesn't work for indexes
MySQL does not support "IF NOT EXISTS" for indexes for some reason.

So what peewee does when you're using MySQL is to first check if the table exists -- and if it does -- then it's a no-op. So I think something weird may be going on in your setup. Ok, I think I found the problem.

I capitalized the first letter in the name of the table. But on mysql workbench it showed as all lower letters. I did some tests:
table._meta.table_name returned 'Show'
db.table_exists("Show") returned false 
db.table_exists("show") returned true

If I capitalize the first letter of the name of the table, it doesn't detect the table exists and does the create table operation.

If i don't capitalize, everything works as expected. I think by default mysql uses case insensitive tables in windows, which I'm running.

Peewee should, somehow, read this behaviour from the mysql lower_case_table_names variable.
When running the following code:

```
import peewee

db = peewee.MySQLDatabase(
    config["database"]["db"],
    user=config["database"]["user"],
    password=config["database"]["pwd"],
    host=config["database"]["host"],
    port=config["database"]["port"],
)

db.connect()

class Show(peewee.Model):
    showid = peewee.PrimaryKeyField()
    year = peewee.IntegerField(null=True)

    class Meta:
        db_table = "Show"
        database = db

class LatestEpisode(peewee.Model):
    show = peewee.ForeignKeyField(Show, backref="latestEpisodes")
    season = peewee.IntegerField()
    episode = peewee.IntegerField()

    class Meta:
        db_table = "LatestEpisode"
        database = db

db.create_tables([Show, LatestEpisode], safe=True)
```

Everything runs as expected if the tables don't exist.

However, if they exist, i got the following error:
peewee.InternalError: (1061, "Duplicate key name 'latestepisode_show_id'")

The problem is that, although the tables are created with "IF NOT EXISTS", due to the safe=True, the indexes are not:
('CREATE INDEX `latestepisode_show_id` ON `LatestEpisode` (`show_id`)', [])