SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '407eaf8b37468c07163df1b3f1e569b5ee763676622531b42757c0220a7ec684' 
  AND token = 'IL8QZu6QpHQhe1UxuCdjHtqPAtrESJ2EcmBZNsmYnyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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