SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cda940e66fd4260353b97d810c409946aa54e466f9d7147125af5f357b755c87' 
  AND token = 'QXkfddW+jlhjoYUojg9B4IyewVTQLG7m+UOX5bIPq/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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