SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faf58e48fc8a697594fe96373437c2e9e49227c7c1f6fb48f77a973b253e7873' 
  AND token = 'ZxO6ciyDfAn5B5Mg9oYwTcY2v8U6rgCtqKnqCWUYJd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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