SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63d7cd1439800450d70debab43b5506125590735f1f6617ac699fba21eb6045a' 
  AND token = 'kg2tTAqXy9SwtL/ahS+kBSUIb8O0YdMJODkRt5B/ckk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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