SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17f9f6d2374c3bad8950364a9a9ddd9a45b9579106c0ff158e70f1d7b2293293' 
  AND token = '4ZpG0vKhDsKVNpO4Q+mwx6qPFphUyf+vIxXrblBSFAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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