SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '395cd1735a851cbfee9abde022cb11a05ac38cbee5a32479bbbdc3a37d462929' 
  AND token = 'aF+r25FglTASLhtMtEG67vA7PjgtBuDmUwQJyEhGUu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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