SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2eb4ab6be96917eae092220277f477486700d207ef9510f9dc5473068b166ef9' 
  AND token = 'I3M5wER7xCT6Fzo+5kH3ywYmAF90j6WibQE28WAX2qg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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