Bring a pot of water to a simmer over low heat; add chicken breast and cook until no longer pink in the center and juices run clear, about 30 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C). Transfer chicken to a plate; cool before shredding into a large bowl.

While chicken cooks, fill a large pot of lightly salted water to a rolling boil. Stir in macaroni and return to a boil. Cook macaroni uncovered, stirring occasionally, until tender yet firm to the bite, about 8 minutes. Drain and rinse with cool water to halt the cooking process until cool to the touch. Add to bowl with chicken.

Add pineapple, raisins, celery, apple, and carrot to the bowl; toss to combine. Gently stir in mayonnaise, sugar, and seasoned salt until evenly coated. Refrigerate at least 30 minutes before serving.