SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4e6f93f5fa9b1f49b019619bb609247138ddaef742306f6627741051db5a5bc' 
  AND token = '++weMeXV/Muaali8z2NbGZyr8nVg8PwDuxPFWaV6cnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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