SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c522f31db8e48be9602e0a378985cc28537498141c289ee6dc96ed907790596' 
  AND token = 'mCni6hg7GMaqiJxHW/fBGHGXKj8xr9cgBzZHTb9b5Zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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