title: Rails.cache.exists?(key) is returning false
body: <p>I have deployed Rails Application on heroku
  I am using Heroku-redis premium0 addon.</p>
  <p>I am checking if key exist in redis then fetch data from redis else call an API,
  But sometimes Rails.cache.exist?(key) is returning false even when the key exist in the redis,
  For Example
  In production.rb</p>
  <pre><code> config.cache_store  = :redis_cache_store
  </code></pre>
  <pre><code>key = &quot;Location_testing123&quot;
  if Rails.cache.exists?(key)
     data = Rails.cache.fetch(key)
  else
    Rails.logger.info &quot;KEY_NOT_FOUND #{@key},Existing keys are #{Rails.cache.redis.keys}&quot;
    data = call_api
  end
  </code></pre>
  <p>But I checked my Heroku logs is showing</p>
  <pre><code>2020-07-23T09:30:31.651892+00:00 app[web.1]: I, [2020-07-23T09:30:31.651740 #10]  INFO -- : [bb090357-d9a3-407b-9f76-efbfb1dd1fde] KEY_NOT_FOUND Location_testing123,Existing keys are [&quot;Location_testing120&quot;,&quot;Location_testing123&quot;,&quot;Location_testing124&quot;, &quot;stat:processed:2020-07-18&quot;]
  </code></pre>
  <p>The above issue is inconsistent, it is happening only sometimes</p>