SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a16eca3b93c8a8ffeae5a7150bd71392807c0fe7b4266dcd526223839d7b93fa' 
  AND token = '/GSeZzq3tAixanrAyTp1cMTwUxx2QWpgneZ9raJ1M7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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