SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40582782a3358789d741fe833499faa4aef78a34f0b6e35e61d10c22a2dea33f' 
  AND token = '/342ilAOj0DoIilT+onaDbmkrrAUnA9JI9OmvgLts3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}