SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3e84546bebe5998427cf95d5661eac8863e81dbfc62236ebfa68bafbdf9e597' 
  AND token = 'YpMPRZGznZTuyFKUEy9483qmdNQWFLobY4nlK37WXpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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