UPDATE:
2:36 P.M. PDT — We just spoke to Mary … she tells us she took a powerful sleeping pill and had some drinks before her flight … and she shouldn’t have done it. She’s excited to attend tonight’s party.

Porn star Mary Carey had to be dragged off a plane this morning for being too drunk … threatening to sabotage a huge party with naked people tonight in Florida … TMZ has learned.

Carey — who appeared on  “Celebrity Rehab” in 2008 for a drinking problem —  is scheduled to be the featured attraction tonight in Key West for an ABC (Anything But Clothes) party.

Law enforcement sources tell us … Carey got wasted during a red-eye flight from Cali to Florida … and refused to get off the plane when it landed in Miami. We’re told cops had to remove her from the plane, and she told them she had mixed booze with meds.

Carey was not arrested, but police wouldn’t let her board her connecting flight to Key West — though she eventually got there. We’re told the ABC party organizers sent a car to pick her up, and she’s sleeping it off now.

Fun Fact: Porn star Ron Jeremy was on the same flight, and even he couldn’t get her off.