SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64bef35125068d4d187d543d05224a3ac865fc651658503351887710486bb05c' 
  AND token = '6wBzexG1ictZhiJJFgkdQVGPbiHi4GZyzaCBz0ORcSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}