SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64448f439a35047fc0ca0c66447efa533fb0e5efe25dd3c4768eddf9ea320c0e' 
  AND token = 'SKo6YBhvcRyMXRGXMmJVtk/tvBV1jKgp5L1KGqaIjVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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