SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '595639af00f0dd0215ea6441efa5b1ed9469bdd494d1a1584bb15b203507dc0c' 
  AND token = 'xH7wuH++pD0c/kf+YC81gl8xwdyRxCrgNxRgcoiDykA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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