SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0114141116ca257b4bedc3dd95532fbfb629c21d8346c75972bfbecd3eb7624f' 
  AND token = 'MDBCe+ZMmg/eCI9DxxS+7HOZ+JjlVxLcomsuq+HIh3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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