SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '692cd3d02adbf324b6f30832724235919a2db6a228756647e4353cd71b35e6b5' 
  AND token = '8UZMWdL0IdNppwGo+goVuFO6zZGp70Xg9JsP28LN0xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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