SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f59f47fdc66fa787c726d72d535080cb994e97df1a43cf656f4cff37a5b8cfb' 
  AND token = 'H5Lin1lnKNQo5Eu2O3oGUN+nJKL1ZiHjXlm/9PRcUKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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