SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60ed6dfb9bd7a01914d89df8954c70e2562a15c408b71285431268060edb1e38' 
  AND token = 'iZlULPumdtIflVJjhK4V+pkhtVbaqtmYxT2XweqkRvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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