SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2bb81707e8291ff2972156eddccb8cce79deeb02c8db9f083685339b29e5d55' 
  AND token = '4AnMygNLvUFNrThXkEvsZAwGlZiAzzsCaVHVlbN1hZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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