SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50e614a2c65f2134cca542f228e065b5cb882ed139bd44ed41236ebebca8b3e3' 
  AND token = '/FeNyh76Mf8OwSrClgFnuSrBYttYWmgHxY5hUFfW+wI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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