SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0fa2e6b96c2780f67ebf04073194125762b0581b3deb5faa44ec462ae861e32' 
  AND token = '2VmqPbqXwsYsNrrGKkWPEwAqudlXqI8G2v5UTpShjLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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