SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bf2de690568480f2d800f8a0aa82740443f0c274785c9b1c418bfb73fca56c9' 
  AND token = '899XfPDVLxw49iHLhLWPh/86ldLnoQPxIxEiW3xIDcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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