Query Entity Framework c # with two types of data

I want to know if I have these two values in my table for verification the data type I get error

using (RARGEntities datosEntity = new RARGEntities())
{
    RegistroDatos datos = datosEntity.RegistroDatos.Where(x => x.CodPersona == CodPersona && x.FechaEntrada = Fecha).Select(x => x).FirstOrDefault();
}