SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fe76a2a5f4800ebf6f3e65af78fbf8b170ec625f7a87d5081e23e5d92b06bdf' 
  AND token = 'cAsnCRtgHQiWItZSb3o2MdypRgdqESzTfw53ayxOP+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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