SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '585e290b1534a2f03f8d436f705049fa446ee8bfdbcd3f9ecf2ca4cb90af8441' 
  AND token = 'SxeRpYT5FGvq6RLz6/TuCttVbHrYC+gQ9/XH74vOOCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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