SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '327d3131e4c87c98788d4d643c8b441a0ffc50a6a200edc9101f877b09554676' 
  AND token = 'kLzh3egvY1HvRjCPh0+XPsidl5PeC8UypBgxIz+9vkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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