SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3d674cf77b1b3f5bbfb7644ccc99ecd8e35b2dece60faa3b602efb85382203e' 
  AND token = 'CjnxmzSHmVjg81Oui0TiQilayCsdHhMk1FsUAKnF124=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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