SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be4aac744e8b648e15f34f991a8aa2c0061df8e0d5575adb0f668d90d34ce93b' 
  AND token = 'ATWA6cWMPEYogznPrgEwueYe41hQyKsMwyk9H1YIXys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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