SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e14a07c1d289a6e9bf421c106450d8a9ed69fcff19882d3e1f7d82eeb2bd381' 
  AND token = 'iPKPNSek679YWRg3KFeXaeN9PHd4vUjrB9XgmeUmDdY=' 
  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"
    }
  }
}