SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc7d28bbebf4c7e4c75543ab95902eee11f22429e3bd42237e18099480bf88d' 
  AND token = 'GiN2aUEmYHUhKFj4ksF5FxqGNv8+RoW1bYR60EYoLn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}