SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '391a2c95b4f1e7a89f198733a5ea5a611f144e3fff9fe52ffb5475017045c952' 
  AND token = 'N5sfAzxNvYxTCIfE3x46g7lX7hKMYEff9mbT4nw9fiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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