SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e963cd749803d36cf853c07a4fcba58220ed30e7f304de16219ad0561bf9af0' 
  AND token = 'MjItPZTyEgcWzTqCSbX8NihuNupLS6RSAiLLMHy9Eys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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