SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '938405e8d67172694d12e71b69a205df84c030bf65d8e6d1aa7445207b4e4a01' 
  AND token = 'dCyh/VfYzE1vuPpWJSYRyqX/P4aqhARm++cBpUZvwhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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