SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b28f03ed1ced468ec4ec9265687041612773a5905804c859b7bb3f8debb48d54' 
  AND token = 'WiiNDL6ynadXZAcMyjHQaBPdsp5EtcxiLdghnLf8gPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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