SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c484418423b48466ca50f440eb116e55c0633fea452842866ad0b4d6fcb622ea' 
  AND token = 'E5iNTsL56fVbSA/LEcbAydJJ9YY0C8dvnGOEJIs63YM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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