SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47617e2af72b66387873b4efc0fd72befbf660da107b9e8fe437fa3d15a3a156' 
  AND token = 'vhGxp0JTE1cktPEA/77YpWEr1A3GoeCh2+17/Oo1QFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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