SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95e7af2bd5e60cb3e249f36e18e41a2500fdfff5e6065d73848da229cdb238a2' 
  AND token = 'Biq2l/tv9A3Odjb7Z0TuugrEImw5GGxK3PkpXCp2UGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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