SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9aae9a1adfa1c5ae0a716dca4072c743b4e6a3cba4e676b1e6832ecf86f8ec4' 
  AND token = 'bDZCfckJ0oRbKFrjVuvcMAN5IytjD2skadXYBgnVu9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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