SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2a711dc2a4a9937d3c3f66f281699a95c6380ef724cf4ef13c04afbafdbb8ed' 
  AND token = 'YgQoeWaJBvpCI4geWiJKy6YBVh8/3Ds2t+86D1jG1nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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