SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '680b7101c85ab668761c548afd00539c0de94217e4b7d29a7729f1474617684a' 
  AND token = 'nG9tudzcAl41UrI2l+aLAMub9BwHhs9xzEjQh04gaPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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