SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '515a571df2526f9c26aaf6468adf3ec8b0277871be707a1e43b35b999f79bbf3' 
  AND token = 'Ohp8zMcYVEnBO6YQLA3IpW/s/99GUKjyzoRI1emLzlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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