SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad79ad04cf19e2524b8f52bf81ba199fa115ac1733acb83a23f9195263c9fae0' 
  AND token = 'z6Qm77AEIw5y2NOTUUww+/juMpJnVrZhOq4UQx/ZyZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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