SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '807a372cb7ad80225611fdea3b0f0009dc38b0531fbf201750939debdc919498' 
  AND token = 'GITUrA3aI4argZENv/uZWvoQEUXg3xqW+sYMQEJuYgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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