SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2623fb1909903085d9d879fccb1ad56d8bd7073b257b049fdf60fdd6b935eed5' 
  AND token = 'fM8LkPBlOLNnVCkbQLWA/iTXYbeUHz4f257seuoWgqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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