SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '690eb9aa25ad626f33d10ed2bb5c0b15dc7502a2ad7d49b96f38ffca7fa47c57' 
  AND token = 'RmhUXdh5PAmXeVdBvRrDMVYzae9VYICZ3MWPQRuUB6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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