I suspect that the LA Times usage is a coinage based on the term African-American as used in the US, and not a term commonly used in Mexico.
In Panama, there are two different groups of blacks. Those who arrived with the Spanish as slaves during the colonial period, and who speak Spanish as their first language, are called afrocoloniales, or more rarely afrohispanos.
Those who came to Panama from the British and French West Indies starting in the mid-1800s to work on the Panama Railroad, the Canal, and the banana plantations are called afroantillianos. Many speak English (and a few French) as their first language, although most speak Spanish as well.
Many Panamanians have some African ancestry (in addition or in combination with European or Indian) and there is much less sense of racial distinctions than in the US. However, those who are distinctly African in appearance are usually called morenos (“brown”), which has no derogatory connotation. (In fact, it may be used as a nickname.) It is considered a bit rude, however, to refer to a person as negro (“black”), but the diminutive negrito is OK.