SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aca7253654097a3aa99950af0280e3404b546ef2a7379d049ca0eccdb8261b4' 
  AND token = 'I/73Q9uU76Eh8KNGFj7VMefvH5R5uQL+YDJgYwY3b3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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