SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c632db0faa5a066a8da3fda9b194ba7adafde04ca4f492f59a84c1276ac53df' 
  AND token = 'M3U+Il4hXqQHGenkM0QXFvFbfH63gPoay9jWVFSPa7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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