SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '401a5b0a4d487764f13844e12306fdf0cb85f5b3ce337bcd5cbed6502024fe4c' 
  AND token = 'Nd6wHIEC2sOYF8CCEPUvNsUbOGfczLTkT2oNUr0z60E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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