SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffe915e58cfa53746bdbc323b69d45cedfb7e1cbb21b5c2d6f99a5e6226e244b' 
  AND token = 'x4gVJNApDjPnwCwcc8x8SXDlhwDkRP0fnl7b+FX+XQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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