SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66dabdcac764a8c8220e5aab61a2b005c1a89843caa95b1f58c79ae9c413a745' 
  AND token = '5m3paRBdHCLMX9Bu+NFpMjwQizqVi/vo5XEY1QF5tnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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