SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9702d848b8f252ee3f3e5d32d741782b6c3d2492d4a0f2ea3193bc93fdba0969' 
  AND token = 'pl6UlN6eJPmISxuLW2gh3TEDGtQUPcjGPs5cI9K1Djk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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