SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '334de581ae7d6830e788e180b755b5a3054519d038082cfdcd2ca3e0b2a49430' 
  AND token = 'gczT65YfaqpjwGiqkn4utQo5WAECWQvhTyq8gf9OiFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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