SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d9d85334979ef81f33cea8dedabf4c839c490a10633d971a5cce3de8dcffe70' 
  AND token = 'YoJsR2XMleyQCJKSH3exiOX5lrPNocTGuLlrdAlB+ug=' 
  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"
    }
  }
}