SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'db2a23f405a11a3f075c0f66ddf8f1991c1efeec45dd6eb8ece124bdce7fdfb7' 
  AND token = 'deVNj7JCuRaHtsktIZdoy/A/sb8+SHJZOCOu/V9fT9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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