SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97534b257c48ec692ca05a864f75b6acaef37bb9109721992286d3c8a00db082' 
  AND token = '1HRlwoxPz+LnwzJ+qFb6MQeLgYqSXYjlOo4LposOaug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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