SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72c3657bbbd7d48b988bd30fcd677b19a21d74f2394033778dae0d37fc9c6244' 
  AND token = 'vGV4IgWprBlFHnWvr4mpbtSCVuUbwWVykQvqIArK38o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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