SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '468d01c33907daeeda57dafce45c6c61cfdcfc30968481859b8bebc5320eb469' 
  AND token = 'PJO0dpL1KDuyRzAJZ6UXlFeGGP/C1200zj4ViMhVmN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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