SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bbace1843fb1e821d9731bba6c3ce80bf9495dbc3388677c852ea25877562df' 
  AND token = 'j9jBgKCkOZnYynqwWajKuKYs2UmTmdzEjVhNA+FwGnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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