SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9dea7c7d9f1fd9e060e19a93dd2e43ed8096755fbdd86e46fee2441816784ce3' 
  AND token = 'pQ676r37ddxiVqMr6iCev3h40jBC5i5p3WM9DLkd9RI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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