SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dd8418257d0e90c9f1d4615b47cba14c1937cd7c476ce012b672cb8391b80a3' 
  AND token = 'XYVwJqQNK6PgDOMAuCtdIGsFinYKqoABjEnTX8a6rbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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