SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '219cb16dbb829311c218be32191a6f9f7e63c3b69f3730cb73e7fba1cefdcb7b' 
  AND token = 'pHpr5TUFJiq/kL+aVrntNloHS9GSLtxpkRvIQpbEr5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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