SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e69103e5406be07afe2539abbae6659aa952a33288493d7842433901956265b6' 
  AND token = 'iEpujofYfyU6eM/OgaLrbXIEDspFdi6bmegopR2wOXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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