Set parameters with HTTP POST in Apex

Yes but you need to use HttpRequest class.

String endpoint = 'http://www.example.com/service';
String body = 'fname=firstname&lname=lastname&age=34';
HttpRequest req = new HttpRequest();
req.setEndpoint(endpoint);
req.setMethod('POST');
req.setbody(body);
Http http = new Http();
HTTPResponse response = http.send(req);

For additional information refer to Salesforce documentation.