SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8db2b95d6eaab28ee33ee12324843b5dcc517f1f66cbad544c6d385b8d4c19ff' 
  AND token = 'bYvTQaYybxgSWAJZgkP2lqFDRgN5WqKSf9w16nYL4HI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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