SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63ca04c43c57aed8e6f9af79fa09f568c85f3bbf42499661da0feb7f354b6719' 
  AND token = 'FWQKwYXekY0QiVahxoidxbomyLf7m/SXqlU4f2GzSWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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