SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a457bd833e6a901ce2175650b67d8db60446e02179d4f30ef885bbb275ff7226' 
  AND token = 'HJfAArpdvr3GAi5KsaRXXYbiZcBWGUAuCt7OfITJi+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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