SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a442647ed737502ae961282805b6b53db2e6b37aac35777232b9f72b723ce98' 
  AND token = '1pzlNrMAhXHUQxYMxmEPZZPlOvviCZWOoHr65CWEdWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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