SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ba568d76d7c4914bda7cc986db2137f6e9a05ca30fc7eadd20f6d5a3c21f675' 
  AND token = 'BBOrBFh/y9EgrYfuScqr/LJqJzJ5KcUxAAbHLzwV7+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}