SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2277dceddeec9d6855e3831e5fc0da9e17144d3045228dcf11e9692bd403346' 
  AND token = '0ramsSv6DScUytqjAxhj/o++FYran5PlKVVju7gftCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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