SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93ece951bb0cad9477236f955d772c0c497a8afc2dcb8fe6b72cae9955a43bed' 
  AND token = 'mSDlJvD8IJPfa7Y6TCHZXWqAfXA6n70Q40rD30xzBfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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