SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8773e8301d252c6b26298b0a4c932b1f5b87538b81d5e9ff5249d8d74fe2045a' 
  AND token = 'YfxHLI4IBgPvSXBbq11+vXf+MRQfZf/FP4MWUj11qxI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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