SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf9f1431b6d972db24388bf42d9e405783d9a9bb8dd1e5b51fa705ab1ff67769' 
  AND token = 'GJTnmKb0qhFcWpyub8WVpRtiByJHKGjTBhaT34Y8nJ4=' 
  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"
    }
  }
}