SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f83ee60e524e24af52cb318e181cfe9f1335b4b01e7438e3e03ec6c61340196f' 
  AND token = '4WSC/WMHAfxYWlaL0RaM/5+bpbCRQK3xfnzywe6sEak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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