SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6730fd88f98217aa82d1e5d86eb133ad394aecb55061387f1d182897cdb45f38' 
  AND token = 'GouGsVNbTmx3Ys5ohHnDQxnAYrQ2x/ONJLOF5vm3dlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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