SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f18554a3e019dd8dcd12cc24b99f5fa1dedc0dca252905a19ebae35884aaa19' 
  AND token = 'CJULFvabtj9dQSI8CLL17zlcMF0GDyOWwm9LjWFOJs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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