SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aedc31cb3eab6a6604e1e73674363f7c5d79a6cdcce10fba5e578baaa64e1cba' 
  AND token = '4YaTcJybcEdYwZRKVTVW5K/ACf9cQl6RGWQjp7iyksk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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