SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '037d4d5ff35c75f1d5dc88e1ac4e1e2eaf88f6a6dc8f97d9d63432c1dd418325' 
  AND token = 'Cxc1YWAFkRhsQDlEQI6Em9WerusEEg5IZm3lHnq2AOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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