SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f914a62299c948b8a76ebc5c7116904cac6abb3eab629acb4c56ab87fe32f9d3' 
  AND token = 'M6fpycWkKxmWusGcB1w+W7uOqoSsVcUC6GaYICa0AS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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