SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90970bbc24db2e7924e2112c844fb69dcbc677417563d10cc30168fba702c6fc' 
  AND token = 'Pu1GM9M5qUMEScOeHyfoFdkdozfjb2NJ/D+K1yPnMbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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