SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c268f1df71f9a54cfa1df57e68b34872f4dddc31db2adc67dce9c80aa0ebd6b' 
  AND token = '2oOGGKC0apX/zt5HRHTIDE5Z0acxeeaCkXYBPbzFAuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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