SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d63fd3537f3f11a750a3f7dd06dbf445cb98ef4ddaec3684d8be51b3ac443cf' 
  AND token = 'iwqtvSpKzbiTSJFvMuh6XCASmcFey5GcWDyh+6g1tuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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