SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ed77bb51b494d08a4166339dbadcce4c3f11b93e2e242d5a6165ce5a61727bc2' 
  AND token = '9pxDBfAdeCX6CztOzwJyfwvywauk64JuUKWxrmma8gQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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