SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faf682ec5d9b41f886b48126ef191676205d6b22eb1cff77ef65f8dd93814e15' 
  AND token = 'FHXlPnZlCApu3vX15sOygGV+ILAfk3xRGZFIFeMe3lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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