Lightweight self-signed certificate

There is API end-point in my local development that should works via https.I generated self-signed certificate using following steps:

1. openssl genrsa -out cert.key 2048
2. openssl req -new -key cert.key -out cert.csr
3. openssl x509 -req -days 3650 -in cert.csr -signkey cert.key -out cert.crt

It works, but many requests to that end-point lead to intensive overhead.Is there way to generate the certificate for maximum lightweight computation?