SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e69a22905f82f279302445535bca5a9b11df93381694e69be2ab2e9afb0580c' 
  AND token = 'DTXMIuxQ9S56S5I7+ecJ0bmAFW81SgAqKPChHdYbYSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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