SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70e2e927a77e00aea5a3037cd7bd2ec0fa9e5a049e5692db572a9b056bb7feb9' 
  AND token = 'K/UWYFVnisCJu4UgFaad6Gt3OCy5nQY6bSvREBFY/3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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