SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9db5189da043ff677ec6440074e361a632f72db437493a008ba0e241a7f8939c' 
  AND token = 'aKAkrjDTj1rWjOhnJ9yEX70/jNA7Dx7ZQVNIs61Kkqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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