SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35cc1189befc1230f498e1e07f0f55e5f27a0dbf18182aaa2250dcd84153cf23' 
  AND token = '9R2ryzVEbjZSnawW+XFpLdl449WxOn3szbZQYpoJoCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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