SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52fc0d55ea103c4eb650dee3f9f8141399f8f91f302fcb259bcafa6c075bb4ab' 
  AND token = 'qneTgXM7YBGLVPLgZbEtg+LQRPGiKcXNJE6l3KHhOsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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