SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fedb3ce99514a27637a792b5870ebbcabeb2745048479bb9dbdf408a6194c91c' 
  AND token = 'V2TcBMwICtu3WGJd8jcx5NoFJUN+gZaMQX2KvubccT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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