SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19acb356210f81da1481afeb57a840d6c00591d2545fbf026213c75cdc7a12bd' 
  AND token = 'SwuKmdIuv03gTg9OhZXkUkIZklEYd93OUKv80OkKbS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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