SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '73d941af2f10727ddd575a487dd2f6f1719dd9da12cf8e320aed476ca3f7d273' 
  AND token = 'mLWAcTr/7o/Gq/3C4UL4rcJzz+emeLN1saEA66Ue9mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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