SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45cc1257eaa9be45654580b408060a89a7cfe2c9011a9df6f722eb7c6d688973' 
  AND token = 'p+POlq1tfi/jBrzMstrHhxeqo+pcxfetvBJHfCQz9Es=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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