SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '65cde7dff8a70276dc4ea5741c44959c24c14e1b4e2b2cc924c11449e64815da' 
  AND token = '95j3MZeOigyMpfHjpnlHWhN3064xc7q0KFDqaaIzFvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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