SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7680aa837b52d151f1623ac794f1d4013a854d7bed6dea1f90a234f7a5839302' 
  AND token = 'g3LyaysQs+dtEwphknDHmPs2oMa8o8COVmqODKCb6xQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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