SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee222c1bc469207fa4e7cb2bbb9171d187346b8b8383728d233824cc4bd0be2c' 
  AND token = 'DvuQZdwy0eOhzGJ+wm10//xlMcSvqP3pPvd7uVkchVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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