SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4df13a20e005a9da6f05a093a59bfda6658d6f38d91bb1e8b13a1955085efbd' 
  AND token = 'XGILmCzK6tzrdczRZebJpxbulZAvd5Zfnw+XHldSn7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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