SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14928155d14d9a338eeaf26238fea6987067d67195293f8d01e989511048377f' 
  AND token = 'bIFfF/aPObUiJgdoeXyIxNZ7oe6uqmRw6ZDYl0yKONQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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