SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25bd365591f51ffa5b68a467b5914bd7550ebd861b4da3d4aedb3021cef5eba5' 
  AND token = 'fs9ZObmyUduUiJEdewfFdkP77HxvJm7zY5onObbSAVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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