SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '612ceb72cd9c1ae7674e24b2d7ce118a962ba527c6ee212c466f01f3de49621a' 
  AND token = 'VrUxGjRXW++SKvdobcO/ATva5gkTri2zZ4qlzw6Gd+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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