Making the Key Exchange stronger

Yes, assuming your OpenSSL supports those curves.. (Probably it does, but doesn't hurt to check by running openssl ecparam -list_curves)

You can read more about the command in the Apache documentation: SSLOpenSSLConfCmd Directive

The set of available SSLOpenSSLConfCmd commands depends on the OpenSSL version being used for mod_ssl (at least version 1.0.2 is required). For a list of supported command names, see the section Supported configuration file commands in the SSL_CONF_cmd(3) manual page for OpenSSL.