SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d513657975677c3283c54b5e3046fd4825b006697236b34380a4793c5493505' 
  AND token = 'ZXKSlf0UIaTqdjvoGtxAMMzWO7s02XLVj5sK8WNNKug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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