SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca5f0b3a54d29eb0ffdb536f421456308fd96b133e2c12db70ba369a87791332' 
  AND token = 'V6w+22st+LXkH9kLqEFYAzCTkTgPC6cVynWdtsml5J8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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