SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddfad5995048d874d6d885829e8a475068a8b327b454eb7a8cac6a3e0a7154bf' 
  AND token = 'OGPJ/uI8Qjyb4uoBpzI7s76VBYVLQaxZawKl7dKqx+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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