SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01cb554683461db66c15768d804802b63f917e2fced588e3b3a3450a9ac9dc00' 
  AND token = 'RyOYJdLOdwmnCVVseVOvY3dKrsU+4AL9I4R235FC6tY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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