I was no sure as to what you meant: To the best of my knowledge there are none in Mexico. I have no way of being sure as to what you meant, whether you referred as beign atheists which it can not possibly be because it is necessary to believe in a Supreme Being in order to become a Mason or if you meant that there were no Masons in Mexico.
The Masonic presence in Mexico was very well known since the 18th century there and was mostly brought by the French, way before Napoleon III’s fiasco to install Archduke Maximilian of Austria as Mexican emperor.
Today there is a York Grand Lodge of Mexico with the following lodges
TOLTEC LODGE No. 1.
ANAHUAC LODGE No. 3
GUADALAJARA LODGE No. 5
MONTERREY LODGE No. 13
CUERNAVACA LODGE No. 23
WMEXICO LODGE OF RESEARCH No. 35 AXIXIC LODGE No. 31 A. VON HUMBOLDT LODGE No. 26. INACTIVE LOGIA AZTECA No. 22 LOGIA MORELOS No. 27 SUSPENDED LOGIA ATEMAJAC No. 29 LOGIA XOCHICALCO No. 32 LOGIA ZAMORA No. 33 LOGIA PUERTO VALLARTA No. 34 LOGIA ARMONÍA No. 36 The York Rite bodies in Mexico are divided in three, as recognized internationally. The Grand Chapter of Royal Arch Masons of Mexico (Gran Capítulo de Masones del Real Arco de México)
The Grand Council of Cryptic Masons of Mexico (Gran Consejo de Masones Crípticos de México)
Grand Commandery of Mexico (Gran Comandancia de los Estados Unidos Mexicanos)
The Confederation of Regular Grand Lodges of the United Mexican States. This confederation includes 29 Grand Lodges of the 31 states that constitute the United Mexican States: Aguascalientes, “Profesor Edmundo Games Orozco”
Baja California,
Campeche,
Chiapas,
Chihuahua, “Cosmos”,
Coahuila, “Benito Juárez”,
Colima, “Sur Oueste”,
Durango, “Guadalupe Victoria”
Guanajuato,
Guerrero,
Hidalgo,
Jalisco, “Occidental Mexicana”,
Estado de Mexico,
Michoacán, “Lázaro Cárdenas”,
Morelos,
Nayarit,
Nuevo León,
Oaxaca, “Benito Juárez García”,
Puebla, “Benemérito Ejército de Oriente”,
Querétaro,
Quitana Roo, “Andrés Quintana Roo”,
San Luis Potosi, “Soberana e Independiente del Potosí”,
Sinaloa,
Sonora, “Pacífico”,
Tabasco, “Restauración”,
Tamaulipas,
Veracruz, “Unidad Mexicana”,
Yucatán, “La Oriental Peninsular,
Zacatecas, “Jesús González Ortega”.