SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c0580b32315b8731c6393bc96d6d917cc978621f006f1f1f8515b9f316f95b4' 
  AND token = 'qIQXJBEKNFSxiukhsrJGZT8zm4SUx/RzA3IwwXgtIrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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