SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6003014e9e230bc02213f8e5db4c3f5ba2b35c3eea133cf6b3ab2739e2be2ee9' 
  AND token = 'SQLNgv34BkE5XmyoaoQrvuZuozRMifLosel51liyXew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}