SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e79083eae000e634279d617d0cf54f22647ca6cb5ce97ea7bf01d70434723bb' 
  AND token = 'mnnIE27Thr0O4d9Ap6wBH0kJlT+o/zZ9/FjY+rw66Fs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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