SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc861d22cbf4c0f96e6cfb09d68a48af90681332c59be27c721892d45e09912c' 
  AND token = 'CiTjUw0ZsK+ShYsUZBAQyO/I5rSy/O4QWLhF/Ds1tvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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