Yes and no.
No, there is no way to apply multiple cores or servers to a single InnoDB transaction.
Yes, you can build a cluster with InnoDB. But it is a Galera (PXC or MariaDB) Cluster, which means multiple servers replicating to each other. Overall throughput increases, but response time for individual queries won't. This could help "load", but not "response time". Is your problem really both?
No, InnoDB does not work in NDB Cluster.
Let's look at one of your slow queries. It may be as simple as making a compound index, or reformulating the query. Or, if you are doing Data Warehousing, creating Summary tables. Please provide
EXPLAIN SELECT ... and
SHOW CREATE TABLE.
Sometimes speeding up the worst query dramatically helps both "load" and "response time", even for other queries.