SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cb0622ed3d6548770c4cd3ce261f697f56be9da10749a3f09bb0431689cf651' 
  AND token = 'VrEPho9Mu00f9eevjRce7tASrJb2pzXCxcJWexMpZUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}