SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83a12016eef5babb11ae5e09f234a58d1431fae84e5a6f4435f451163cb4da79' 
  AND token = 'dWzrVQ0Amv5oGmDyhLHxQRzSRkk6YpG/s9yxGZ6lwdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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