SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '869b5779431e8aa03e2f6e0dff72a5dd8db1d96d5ced6b404b1fa065e7cae484' 
  AND token = 'vx2UehT68XP6PhP60zMmZI6s/kiBiQPEF1nKPHYEjng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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