SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '98aca45355d5fd40fd2f3f3ecebb684ab6d758fece57b282176d518638e5d953' 
  AND token = 'MJFVKL0gK7OQ0Pvb6inn2SJH8JIuKVvZ+TVz5zPBY5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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