SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'baf29083f3191a7e7e33b172bae33faabc69acbbaa76e917bb4679d4e153bdd5' 
  AND token = '96RlGIqBuhviieRWeACCvOuaOw3/Xniw22zhl/cFyg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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