SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '540172acc7674d6bd597b10291c662171efdcceaf9b9de2387be336fe7b2c5c1' 
  AND token = 'LeSz4faYbV7EpEQF0lrUNtkkoBgVjoSperSSmtOkAnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}