Add table index for keys.userid & keys.key

[coolbung]

On a high API transaction site, the queries for this table are running rather slow due to the absence of indexes. So indexes need to be added for the following columns in the keys table

• userid
• key

[coolbung]

Added separate keys for hash and userid in the keys table. This is since the query profile hardly has both in the same query.

Index also added for hash on logs table so that the rate limiting can be made functional at some point.