SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed474ac7d32b9173097106511a9238f98899c936b1a8ee62e68ecbd624f76f62' 
  AND token = '1QuCAAsXQaPap0XiI35GUcqlOKvVhIqvZyhYK2HPB2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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