SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7256ea7a594c12063ceca8d3ef6ae95a6659c0bc74e607ed1cda3c9ab1741a5f' 
  AND token = 'AfTM8xsoDRugJa1seYLENOIS+Mbxb8iivOAqgB+hGb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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