SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '154a7011196363847f3f31de2605b2505ffd88a7902a901d6e468671beec120c' 
  AND token = 'ztu1wW/RlvELvDpDynwCFx20bRW3yXM7Fle9yhr021E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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