SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54d8c9e205802e7498dda69810e62023a110b7951d792bf672dce0c5c511da98' 
  AND token = '3Ye2TipMGy/rJo7IDHeIRqKbCFnPDhXUyY1ud34HFqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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