SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0983b6f1dffcb0789073f2ea248a93115ba11c9755c5f182131a5485740b64ea' 
  AND token = 'juPnlHJzPnOqJf5VSrn0Rqw9XEvZk037zhWTQRSzAGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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