Sounds kind of like indigestion. It makes for a tightness of the chest. Could be caused by a lot of things; fried pork rinds do it for me.
Since you noticed this immediate reaction to a scone, try a gluten elimination diet. That means nothing that contains gluten--which is most commonly found in wheat, but is in other grass products. In the UK all of the products are labeled with allergy information, so it's easy to find. In the US, only some list out allergy stuff, and then they may only list tree nuts and not list gluten. So look for gluten in the ingredients section and wheat. I can't remember if it's corn or rice (or both) that also contains gluten. I'm sure you can find out more information online about what is and isn't gluten and how to spot it in the ingredients section. Cut it out and see if you have that same reaction when eating anything else.