SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd23b8005e130bfe6bcb569ea61adfcef36fae9884f0aba9902c5a0ee352ab0bf' 
  AND token = 'vnWk0DlU0cEKvJneyNERw6nbOC3KSrtO62iFBtiHgnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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