Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3efd639571c4196c808d5c304061bf7065d652f1430591302f0821f672809111' 
  AND token = 'dNJ7aTwtpBT6ly8lMTQLQdRDIBsuJz4fjsV6+of10ow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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