SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ff4095914534d080040897081833453bdc6141ea626664b530282acdef8e95a' 
  AND token = 'wFCtunWRNM5xN+sEY9e1rIHDbAPbxoK22QLmfr14dUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}