SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f5bca2854e9a1a93dd028a6f850ddb1661982962770aa37a22ec2eca2895a97' 
  AND token = 'vyPNcw6oZIcIxWnCnRrYwfOWZ477QWjG2TV/OrUR7eo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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