SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bd570e66ba7f7ffd84fb9b4a8bd4c3a9cb79b8043c7afcb9a9a888a0a424c110' 
  AND token = '4kHpf9DfsM/obseN4wQrh9U99gSW4DWRpQ/v9/zg708=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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