SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '114574f99e1008fa5681dd1c99e3aa3bcee8f64bc2bc35a426dd4d6bf78a68f7' 
  AND token = 'AuMZzWj+Ec5KegpFq7AOCqQQQFEKi5JmBVnJsjYpI7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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