SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18d77cbe7a43b427c4a8ce12bc11d658f225d830d9098fa364fa8af60367050a' 
  AND token = 'Ead9d/xEM3lnRGLv63HpYZNDUJrBhHDBs/zm1KWOxOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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