SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46db5fca0873967d96caf7bfb0a5c113b4b17efe098800beea24a7560132e4f2' 
  AND token = '5WVrjD13HVpDlAQUA5+R2sYsByYvTVxSSofe8GWa194=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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