SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fee1de5e9f2f69a47f59cd364a2c2d8373f20b48bd8caef84d8a8fc4036a28c' 
  AND token = 'hd1KlK2GVxczmP1IY3FlreXHJj6X+kvKuJnDMfjkLrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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