SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c04ee8176cbf8fa2415d46f0b5bd2e027c72d585c211f6e22671c56737f04c1' 
  AND token = 'ijtQmrLfLaObCZ57YWfIkJFomJwue3fuEKB0fvdQtNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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