[Backport] Add indexes to timestamp field in oauth_nonce

[gelanivishal]

Original Pull Request

magento#13328

Description

Inclusion of indexes into timestamp field in order to avoid deadlocks while on erasing old records.

Fixed Issues (if relevant)

1. Deadlock occurs using REST API & OAuth 1.0a under high concurrency  magento/magento2#10346: Deadlock occurs using REST API & OAuth 1.0a under high concurrency

Manual testing scenarios

1. Pull the code and run php bin/magento setup:upgrade
2. Create thousands of OAuth 1.0a requests to REST API (eg concurrency of 5 / sec)
3. Requests should complete successfully

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)