SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7277c8c8003a4fc5a50265bfe8f360cb319e3b671cfc3bb60c8702531a32064d' 
  AND token = 'gsRaDbH76YQtH/oWDKN7HU/EmhuSJ9nQVj+I9tJ++FU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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