SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acdfb5cfd983640898786363532dcb30c8b948210b0fff35a5c0f5d25ff699b6' 
  AND token = 'rkjQPqwJlZ0GenKJxo0IXGjx4K11HDkYYBMGZBkgYIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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