SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce5b83f1210f4051a9d1876ba10487e90597dd726cbf5a2896f90dbde5e1c49d' 
  AND token = 'qCB5qfndP5wUKBUt665C+KyswLSWEXjhGcELoLxaPvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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