SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a558fc59d5526656238ef90f2b6337318ae1445b8341c6f38d380dcb3f48c73f' 
  AND token = 'Jly3bgJUTzhkdSP3+X7tdiRzgmQe/k62Ec3gWSxrD2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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