SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2752bd4b9150a8c697a6e85c8c9545f8025f2e54ac966658e8061f13347ff6c' 
  AND token = 'nZzx2LZQzzgvWVDwnpa22+iSia2MvjQeUfQ2JZUgVFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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