SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82162c92e238951b4c42f5ac36890e92aa1237e9bf3f6d69af9bf0da52bddb39' 
  AND token = 'zK2skO0v6AusUvTqTkPldIG07ZPyCzPUf5IZp55CiQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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