SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5ed102d3bf36333190ba817f19ae693fbe28e161cdd20d43ead090ab654e1ee' 
  AND token = 'iafTu9u11EWkt0gjnQoyNa1Rp2MTX1BrkfYnU+oJing=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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