SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4f96cd0ac9e8b970015d9d9e310c1d353cff29437bea7137136f18f8e58b6ff' 
  AND token = 'quJxRD7vY7r6qHLdA7W5FqhkwRQZh/YnIW57mFp9KxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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