SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8be09975cf51e29f43f6647c685cf72694a383164a8bba620a2283573ce40ad' 
  AND token = '8PkRWsNfkO3zgPXHqZb4zb7TNeciM88StUQ6I6UJSTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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