SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dd797b274d259d501bfe34cfbd5c50a84b8d4f214fa20c9605827301364f0439' 
  AND token = 'j6l15V/rpDqFEycbukOhqnt7auknvxPfwFV2y2xBMpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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