SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '72f2a8dcd9b2f8ea319ef122dbc846580dbcd4cb08b5641f1fbe516d10375004' 
  AND token = 'uMVasWRqAwrCp3poK5ZuZ9KJ7j2S0pZCzjXmI+UGQ4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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