SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b0447aef1e5708775c75a5e296bff51be2e4894bffd1dd76bdc1537908a60db' 
  AND token = 'JVnNY6IWDUzupiJVVhWna/lv/yVJ+vT6FofsmmM4vNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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