SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65d80fd6bc5d26b1753c46fbbf4eb843a5acab0a8b4cda627fb284ca6c83f999' 
  AND token = 'Gxgr7k/v2f3ZIlSzsArSvlgUGlt1ptd+epu4OoYUQJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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