SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33f52165ac5ae1fb83accc1f649693b4a83a3509da7638f102668f8e46ec95a4' 
  AND token = '+z+IE2pA5LRHyxaXd9wrihbcWJ1nWfTjtN3kcp9ItPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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