pub const SELECT_WAITPOINT_FOR_DELIVER_SQL: &str = "SELECT token_kid, token, waitpoint_key, execution_id \
FROM ff_waitpoint_pending \
WHERE partition_key = ?1 AND waitpoint_id = ?2";Expand description
For deliver_signal: read kid + token + wp_key + bound execution. Returns (token_kid, token, waitpoint_key, execution_id).