Which AWS service is a key-value database that provides sub-millisecond latency on a large scale?

Explanations:

Amazon DynamoDB is a fully managed NoSQL database service that provides key-value and document data structures, offering single-digit millisecond latency and sub-millisecond response times at scale.

Amazon Aurora is a relational database service compatible with MySQL and PostgreSQL, designed for high performance but not specifically a key-value store.

Amazon DocumentDB is a managed database service designed for document data, specifically compatible with MongoDB, but it does not primarily function as a key-value store.

Amazon Neptune is a graph database service that supports both property graph and RDF graph models, not a key-value database.