SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53b634d86b86e776c0e64494ac091c72dfbc413ebfb2417d55eed8c9fbc0a47d' 
  AND token = 'aCtSstlu8CvWRZUNgptYa4Mx9CeapaAiLWBT6eAxCq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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