SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91cd53fb2ce5dc620b890132e39242c65f1127b0e72cdcf2c0af1d5fdce999e1' 
  AND token = 'VrYZB05/YnSfBrzZHEh+6QIFp82r/MgRVUvcGedfAyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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