SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bac5962c668ddd241746419ebde38dccff4c9847ce27393552689be528f0972' 
  AND token = 'hz1duFtdDN8b0mZwwLbISeiDMFMjC3YuSTwFQV9thsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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