SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12208692e9646e1b3aa16bf8527c4a224d7dde535df0193121f720f4a2480402' 
  AND token = 'IDFQL0DIoPfSn9LiyRYXp5N5hA3tZrNunuCh9KFsbAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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