SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e14a04878863c5621dd2f32711a97e4cb2eec6dde49d4bfcfb8a8e185262aa9' 
  AND token = 'kX2IsJkOY77yjJv2WjSz3iPNUKAo8E16pw321XPuIow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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