SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '228c19044f80e895231d3d283633de5a674399575603c0b577bcd688f448b8f6' 
  AND token = 'JVAgLrOAVeAhYq25jslUir7XoQFW3CX+LNv8ccF/iW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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