SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'be997128fc60f107d77ded28a5fb435e50e7466eba551f4c52b605cf638346b8' 
  AND token = 'AbNjLt46pauI49rfF7H7GG4AV4Kwrjw2X8SxeZj7lnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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