SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '518f49231a1527d80b46075654d84363ba722f6884e723dd4ff6eba3dcff12ce' 
  AND token = 'NtKMyFe0rnBNhd2jHOVPq6tILXK+iXZyyvuUdd0HE9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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