Touch isn't supported in text protocol

[bigbes]

Touch

The "touch" command is used to update the expiration time of an existing item
without fetching it.

touch [noreply]\r\n

• is the key of the item the client wishes the server to touch

• is expiration time. Works the same as with the update commands
  (set/add/etc). This replaces the existing expiration time. If an existing
  item were to expire in 10 seconds, but then was touched with an
  expiration time of "20", the item would then expire in 20 seconds.

• "noreply" optional parameter instructs the server to not send the
  reply. See the note in Storage commands regarding malformed
  requests.

The response line to this command can be one of:

• "TOUCHED\r\n" to indicate success

• "NOT_FOUND\r\n" to indicate that the item with this key was not
  found.

https://github.com/memcached/memcached/blob/master/doc/protocol.txt