SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8a5bc99db0ce9171afde36afb230ec872b48cd35bc675e1e52081df652dc2cb' 
  AND token = 'lXe1w+dVFRzynnbhza4jD7uZTVXjeGjaOrvyK3pg3wM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}